
You have another email client set up as POP3, which is collecting your emails before Mailbird is able to do so.Then, update the password (see screenshot below) to whichever new password you have set.Double-click on the account which isn't currently sending or receiving emails.the three horizontal lines in the top-left corner of Mailbird)
You will need to reauthenticate yourself in Mailbird in order to fix the problem.
If you have changed/updated your password for your email account, then Mailbird will not be able to send or receive your emails until you update here as well.
You recently changed your email password. If you are able to now send and receive emails with your antivirus or security software disabled completely, you will need to reach out to your antivirus or security software provide to obtain guidance on how to whitelist Mailbird, since it will not be able to work otherwise. If you can't seem to whitelist Mailbird, we suggest exiting/disabling completely your antivirus software while using Mailbird, in order to see whether or not you are now able to send and receive emails. We therefore strongly suggest that you first try 'whitelisting' Mailbird in whichever antivirus/security/firewall software you are using, and then try sending or receiving an email once again. This is by far the most common reason, and it is unfortunately beyond our control. If you have a Windows 11 Operating System, we strongly recommend that you follow the steps contained inside this separate article, in order to add Mailbird as an exception to your Windows Defender. If you have a Windows 10 Operating System, we strongly recommend that you follow the steps contained inside this separate article, in order to add Mailbird as an exception to your Windows Defender. Oftentimes, this is caused by Windows' native firewall, called Windows Defender. The most common reason for not being able to send or receive emails is your antivirus/security software or firewall restricting Mailbird's access. Keep in mind that you may need to carry out more than one of these suggested steps in order to start sending and/or receiving emails again. Normally, these steps are very effective at resolving the problem of not being able to send or receive emails, since they are the most common reasons, for which (fortunately) we have some very good solutions. If you are experiencing issues either sending or receiving emails, in this article we will offer some suggested steps which should hopefully resolve the problem.