Mozilla Thunderbird

You can work with Yandex.Mail using Mozilla Thunderbird.

  1. Step 1. Configure your mailbox
  2. Step 2. Create an app password
  3. Step 3. Configure IMAP-based client
  4. Troubleshooting Mozilla Thunderbird issues

Step 1. Configure your mailbox

  1. Open the “Email clients” section in Yandex.Mail settings.
  2. Select the following options: From the imap.yandex.com server via IMAP and App passwords and OAuth tokens.
  3. Save changes.
Note. If you want the emails to be kept for some time after they are deleted in the mail client, select Don't automatically delete emails marked as deleted in IMAP. Please note that they will be permanently deleted from the mailbox immediately after restarting the mail client.

Step 2. Create an app password

  1. Go to Account Management.
  2. Under Passwords and authorization, click Enable app passwords. Confirm the action and click Create a new password.

    If you have two-factor authentication enabled, just click Create an app password.

  3. Select the application type Mail.
  4. Come up with a password name. For example, you may enter the name of the app you're creating the password for. The password will be displayed in the list under this name.
  5. Click Create. The app password will be displayed in a pop-up window.
Restriction. You can only see the created password once. If you entered it incorrectly and closed the window, delete the current password and create a new one.

Step 3. Configure IMAP-based client

  1. Launch the program and click Skip this and use my existing email in the welcome screen.
  2. Enter the following account details in the Configure mail account window:
    • Your name — your username (for example, “Alice Little”)
    • Email address — your Yandex email address (for example, “alice.the.girl@yandex.com”)
    • Password — The app password you created for Yandex.Mail.

    Click Continue.

  3. Click the Manual setup button and enter the following parameters for the mail servers:
    Incoming mail
    • Protocol — IMAP
    • Server name — imap.yandex.com
    • Port — 993
    • SSL — SSL/TLS
    • Authentication — The app password you created for Yandex.Mail.
    Outgoing mail
    • Server name — smtp.yandex.com
    • Port — 465
    • SSL — SSL/TLS
    • Authentication — The app password you created for Yandex.Mail.

    Also provide your Yandex login as your username (for example, “alice.the.girl”).

    Attention. If you are configuring email delivery from a mailbox such as “login@yandex.com”, your username is the first part of the address before the “@” symbol. If you're using Yandex 360 for Business, enter your full email address as the username.
  4. Click Re-test to verify that the entered details are correct. If the test was successful, click Done.
  5. If you want to use Mozilla Thunderbird by default, click Set as default in the System integration window.
  6. Right-click the account name and choose Settings.
  7. Go to Server settings and in When I delete a message, select Move to deleted items folder.
  8. Go to Copies and folders and enter your Yandex mailbox name for all the folders.
  9. Click OK to apply the changes and restart the program.

Troubleshooting Mozilla Thunderbird issues

This step-by-step guide will help you solve issues with Yandex.Mail and the email client.

Select a problem:

Which message is it?

Try logging in on the Yandex.Mail website with the same login and password that you use in the email client. Enter your username and password manually without using auto-fill.

Note. If you're using the app password to log in, make sure that the options From the imap.yandex.com server via IMAP and App passwords and OAuth tokens are enabled in the Yandex.Mail settings.
Were you able to log in?

It means the problem occurred because you didn't accept the User Agreement for Yandex Services. It is accepted automatically when you log in to Yandex.Mail for the first time.

If you are a part of a company and all the mailboxes with this domain experience this problem, you need to log in to Yandex.Mail for each of them. There is no way to do it automatically for all mailboxes at once, because each Yandex.Mail user must accept the User Agreement themselves.

Go to Email clients in the Yandex.Mail settings. Make sure that the From the imap.yandex.com server via IMAP option is selected and the correct authorization method is specified.

Make sure your email client settings are configured as follows:

When using IMAP
Incoming mail
  • mail server address — imap.yandex.com
  • connection security — SSL
  • port — 993
Outgoing mail
  • mail server address — smtp.yandex.com
  • connection security — SSL
  • port — 465

Open Yandex.Mail and go to Settings → Email clients. Make sure you have the From the imap.yandex.com server via IMAP and App passwords and OAuth tokens options selected.

When using POP3
Incoming mail
  • mail server address — pop.yandex.com
  • connection security — SSL
  • port — 995
Outgoing mail
  • mail server address — smtp.yandex.com
  • connection security — SSL
  • port — 465

Go to Email clients in the Yandex.Mail settings. Make sure that the From the imap.yandex.com server via POP3 option is selected.

See Data in transit encryption for more details on checking server settings in different mail clients.


If you were unable to log in, the credentials you entered may have been incorrect.

If you see a message that says “Authentication required”, “Sender address rejected: Access denied” or “Send auth command first”, authorization for the Yandex SMTP server is disabled in the mail client settings. Make sure that the Check user authentication (for Outlook Express) or SMTP authentication (for The Bat!) is enabled.

Also try logging in to Yandex.Mail with the same login and password you use in the email client.

Note. If you're using the app password to log in, make sure that the options From the imap.yandex.com server via IMAP and App passwords and OAuth tokens are enabled in the Yandex.Mail settings.

If you logged in successfully without any errors, this means the problem occurred because you didn't accept the User Agreement for Yandex Services. It is accepted automatically when you log in to the Yandex.Mail web interface for the first time.

If you are a part of a company and all the mailboxes with this domain experience this problem, you need to log in to the web interface for each of them. There is no way to do it automatically for all mailboxes at once, because each Yandex.Mail user must accept the User Agreement themselves.

If you receive the message “Sender address rejected: not owned by auth user”, the address in the From field doesn't match the address that you've specified in the mail client settings for SMTP authentication. Correct the address and re-send the email.

Also try logging in to Yandex.Mail with the same login and password you use in the email client.

Note. If you're using the app password to log in, make sure that the options From the imap.yandex.com server via IMAP and App passwords and OAuth tokens are enabled in the Yandex.Mail settings.

If you logged in successfully without any errors, this means the problem occurred because you didn't accept the User Agreement for Yandex Services. It is accepted automatically when you log in to the Yandex.Mail web interface for the first time.

If you are a part of a company and all the mailboxes with this domain experience this problem, you need to log in to the web interface for each of them. There is no way to do it automatically for all mailboxes at once, because each Yandex.Mail user must accept the User Agreement themselves.

If you receive the message “Username failure or POP3 disabled”, the mail program cannot access the mailbox over POP3. Make sure you entered the correct password and the POP3 protocol is enabled in the settings under Email clients.

Also try logging in to Yandex.Mail with the same login and password you use in the email client.

If you logged in successfully without any errors, this means the problem occurred because you didn't accept the User Agreement for Yandex Services. It is accepted automatically when you log in to the Yandex.Mail web interface for the first time.

If you are a part of a company and all the mailboxes with this domain experience this problem, you need to log in to the web interface for each of them. There is no way to do it automatically for all mailboxes at once, because each Yandex.Mail user must accept the User Agreement themselves.

If you receive “Message rejected under suspicion of SPAM”, it means that Yandex.Mail determined that the contents of your email is spam. To resolve the problem, go to Yandex.Mail and send a test email. This shows the system that messages are not being sent by a robot.

Check your computer for viruses using free antivirus programs, like CureIt! by Dr.Web or Kaspersky Virus Removal Tool.

For more information, see I got the message "Email can't be sent, because it appears to be spam".

If you receive the message "Bad address mailbox syntax", check the address in the From field. Correct the address and re-send the email.

  • Make sure your email client and your computer internet connection are set up correctly.
  • If you use an anti-virus program, firewall, or proxy server, disable them and see if the problem persists.

  • Enter your valid personal details in Yandex ID and link your phone number to your account. It may be that our security system considers your account suspicious and blocked the mailbox. This usually happens if you don't link a phone number to your mailbox or enter a fake name in Yandex ID. It usually takes a couple of hours to have your account unblocked.

  • Also try logging in to Yandex.Mail with the same login and password you use in the email client.

    Note. If you're using the app password to log in, make sure that the options From the imap.yandex.com server via IMAP and App passwords and OAuth tokens are enabled in the Yandex.Mail settings.

    If you logged in successfully without any errors, this means the problem occurred because you didn't accept the User Agreement for Yandex Services. It is accepted automatically when you log in to the Yandex.Mail web interface for the first time.

    If you are a part of a company and all the mailboxes with this domain experience this problem, you need to log in to the web interface for each of them. There is no way to do it automatically for all mailboxes at once, because each Yandex.Mail user must accept the User Agreement themselves.

  • "Bad address mailbox syntax" Check the sender's address in the From field. If the address is incorrect, you'll see the error:

Read our step-by-step email search instructions. Before you start, open Yandex.Mail in a new tab.

Select a problem:

When you delete an email message, it is sent to the Trash folder, where it is stored for 30 days. Messages can be restored during this period:

  1. Go to Trash.
  2. Select the messages you want want to restore.
  3. Click To folder.
  4. Choose the folder where you want to move the selected messages, like Inbox.

Email deleted longer than one month ago cannot be restored — they are permanently removed from the Yandex.Mail servers.

If email messages are not in the folder where they should be, they probably ended up in another folder, such as Trash or Spam. If you remember the sender's name, address, or a part of the message text or subject, try to search for the message in all the folders in your mailbox.

Did you find the messages?

You can recover email:

  1. Go to the folder where you found the email.
  2. Select the messages you want to restore.
  3. Click To folder.
  4. Choose the folder where you want to move the selected messages, like Inbox.
Why email disappears and how to avoid this

Emails is stored in the Trash folder for 30 days and in the Spam folder for 10 days. Afterwards, they are permanently removed from the Yandex servers. Why email may end up in these folders without your knowing it:

Another user has access to your mailbox.

Messages may be deleted by a user who has access to your mailbox if you forgot to log out on someone else's device. To end the session, click Log out from all devices in the account menu. You can also do this in the Yandex ID settings using the link Log out on all devices.

Go to the session history log and check for any delete email operations.

Restriction. The log stores about 2000 operations. If more than 2000 actions were performed after the messages were deleted, data on the delete operation will not be displayed in the log.

If you are sure that only you have access to your mailbox, test your computer with an antivirus software, change the password and alternative address. You should also make sure there aren't any unknown phone numbers on the Phone numbers page.

Email gets lost in the mail client

If you use an email client and delete email in it, messages are removed from the service page as well. This is because your client uses the IMAP protocol, and the inbox in your client is synced with the service. You can delete messages from the client, but leave them in Yandex.Mail by configure the client using POP3, but we don't recommend this as messages might not sync correctly with the server.

This is a filter that deletes or moves email messages

Make sure there are no mail filters that delete incoming messages or move them to other folders. If this is the case, temporarily disable them and check if messages arrive in your Inbox folder.

If you don't find the email manually or with a search, this means they can't be restored — they have been permanently removed from the Yandex.Mail servers.

Why email disappears and how to avoid this

Emails is stored in the Trash folder for 30 days and in the Spam folder for 10 days. Afterwards, they are permanently removed from the Yandex servers. Why email may end up in these folders without your knowing it:

Another user has access to your mailbox.

Messages may be deleted by a user who has access to your mailbox if you forgot to log out on someone else's device. To end the session, click Log out from all devices in the account menu. You can also do this in the Yandex ID settings using the link Log out on all devices.

Go to the session history log and check for any delete email operations.

Restriction. The log stores about 2000 operations. If more than 2000 actions were performed after the messages were deleted, data on the delete operation will not be displayed in the log.

If you are sure that only you have access to your mailbox, test your computer with an antivirus software, change the password and alternative address. You should also make sure there aren't any unknown phone numbers on the Phone numbers page.

Email gets lost in the mail client

If you use an email client and delete email in it, messages are removed from the service page as well. This is because your client uses the IMAP protocol, and the inbox in your client is synced with the service. You can delete messages from the client, but leave them in Yandex.Mail by configure the client using POP3, but we don't recommend this as messages might not sync correctly with the server.

This is a filter that deletes or moves email messages

Make sure there are no mail filters that delete incoming messages or move them to other folders. If this is the case, temporarily disable them and check if messages arrive in your Inbox folder.

If new messages are not in the Inbox, they most likely ended up in another folder, such as Trash or Spam. If you remember the sender's name, address, or a part of the message text or subject, try to search for the message in all folders in your mailbox.

Did you find the messages?

If you found the email in Trash, Spam or another folder, you most likely set up filters that delete messages or move them to Spam or another folder. If this is the case, disable them temporarily and check if the messages arrive in your Inbox.

If the new messages are still missing, check that you entered your email address correctly on the website you expect to receive email from. Find out if the sender wrote your email address correctly.

Check that the site's or sender's email address hasn't been blacklisted.

Enter your valid personal details in Yandex ID and link your phone number to your account. It may be that our security system considers your account suspicious and blocked the mailbox. This usually happens if you don't link a phone number to your mailbox or enter a fake name in Yandex ID. It usually takes a couple of hours to have your account unblocked.

If you delete emails in your mail client, but they are still in your Yandex.Mail folders, it is likely that your mail client uses POP3. Due to certain features of the POP3 protocol, email client mail may not sync correctly with the server. We recommend using the IMAP protocol for Yandex.Mail. For details on how to switch between POP3 and IMAP, see Switching from POP3.

If your mail client doesn't display sent email, it probably means that it uses POP3. Due to certain features of the POP3 protocol, email client mail may not sync correctly with the server. We recommend using the IMAP protocol for Yandex.Mail. For details on how to switch between POP3 and IMAP, see Switching from POP3.

The report always refers to the cause for non-delivery. You can read about the most common reasons in Non-delivery report for Yandex and Non-delivery report for other address (not Yandex).

If during the activation of SSL-encryption you get errors about an incorrect certificate, make sure that the mail client and the operating system are configured correctly:

  • The correct time (without any delays and “dates from the future”) is set on the computer. If a wrong date is set, the system erroneously defines the certificate period as not yet started or already elapsed.
  • All updates of the operating system are installed.
  • Checking of the HTTPS-connections is disabled in the settings of your antivirus software To change the settings of your anti-virus software, check the guides for Kaspersky Internet Security and ESET NOD32 Smart Security in the Security certificate errors section.
Add the certificate to the list of trusted certificates manually (Windows)
Attention. If you are not sure that you can install the certificate yourself, contact a specialist.

To add the certificate to the list of trusted certificates:

  1. Download the certificate. (If the file opens by following the link directly in the browser, press CTRL + S and save the file on the computer; there is no need to copy the text from the file.)
  2. Open the Start menu.
  3. Enter certmgr.msc in the search field and press Enter.
  4. In the program, click on the Trusted root certification authorities folder in the folder tree.
  5. Right-click on Certificates in the right part of the window and choose All tasks → Import.
  6. Click Next.
  7. Click on View and select the earlier downloaded file CA.pem. Tap Next.
  8. Leave the default settings in the Storage of certificates section and click Next.
  9. Click Done.
  10. (Optional) Click Accept in the popup window.
  11. Click on the folder Trusted root certification authorities → Certificates in the folder tree.
  12. In the list of certificates (on the right), find the certificate Certum CA, right-click on it and select Properties.
  13. Go to the General tab.
  14. Make sure that the option Server authentication is enabled in Allow only the following destinations.
  15. Click OK.
Adding the root certificate to Linux
The information on adding the root certificate is provided in the instructions Adding CAcert root certificate to Debian/Ubuntu.
Problems with confirmation of the certificate in The Bat!

If you have problems confirming certificates in The Bat! mail client, update the program to version 6 or later. Perform the following actions after the software upgrade:

  1. Choose Properties → S/MIME and TLS in the program menu.
  2. Set S/MIME Implementation and TLS certificates to Internal.
  3. Click OK.
  4. Try sending an email. If you get another certificate error, go back to Properties → S/MIME and TLS → S/MIME implementation and TLS certificates and set it to Mircosoft CryptoAPI.
  5. Click OK.
Note. You need to switch the options manually because Internal only works in some versions of The Bat!, whereas Microsoft CryptoAPI only works in others.

If after all this the problem still persists, contact the Ritlabs support service.

Reconfiguration of your send script fails

Try to compare your code with the guidelines in the network:

1C software does not support SSL

To support SSL, install additional Stunnel software:

  1. Download the latest version for Windows (stunnel-version-installer.exe) from https://www.stunnel.org/downloads.html.
  2. Unpack the archive
  3. Execute file mailssl.bat as administrator.
  4. Disable SSL in the mail client settings and specify the following parameters of the servers:
    • SMTP: server — localhost, port — 25
    • POP3: server — localhost, port — 110
    • IMAP: server — localhost, port — 143

If you have changed the mailbox password recently, make sure that you also update the settings in your email client. If the password in the settings is correct, wait a few hours – the mail client settings may not synchronize with the Yandex server immediately.

Try logging in using the same username and password in the web-interface: enter the authentication data again. If you're asked to enter captcha characters, you can check a list of possible reasons in Why do I have to enter captcha numbers during authorization?.

Go to Email clients in the Yandex.Mail settings. Make sure that the From the imap.yandex.com server via IMAP option is selected and the correct authorization method is specified.

Attention. If you're using Yandex 360 for Business, enter your complete mailbox address as your username.
Make sure that the IMAP or POP3 protocol is enabled in the Mail clients section.