Dear customers,

today we show you how to set up the Thunderbird eMailclient correctly. Obviously there are sometimes problems that cause error messages when using the default settings.

Important to know:

We use Postfix as mail server for sending (MTA) and Dovecot for receiving (imap/pop3).

These are also the most frequently used mail servers and almost all of them use them. 

For the retrieval of the mails and also the dispatch it is important to transmit the mails only encrypted and/or to transmit the login information only encrypted.

Often a connection is established with the standard settings unencrypted on the standard ports 25 for sending or 110/143 for receiving. 

A certified connection (TLS certificate) is required for encryption. Postfix can only use one certificate for one domain, therefore the mail server name must always be entered as SMTP and IMAP server in the email program and not as suggested e.g. or

An example:

You are on the server with your domain. Then you have to enter as SMTP and IMAP or POP3 server name in the email program and not your domain name or anything else. Then it works without error messages.

Setup with Thunderbird:

From the Thunderbird main menu, click Set up account: e-mail and then enter your login data for the mailbox in the window. For Plesk servers, the login name is usually the email address. On Confixx servers the username is e.g. web123p1 .

Then click Next.

Then Thunderbird checks the settings. Mostly they don't fit, so click on "Edit manually" afterwards.

With this example you can set Thunderbird. But please use your server name and your email address. This is just sample data.

Important is the eMail inbox, i.e. IMAP as a rule, so that the emails can also be retrieved and processed with other devices and the authentication.

Here we then select "Encrypted password" with an SSL/TLS connection on the standard ports 465 for sending or 993 (imap) for receiving.

The outgoing mail server must be the server name on which you are located.

It wasn't that hard, was it? Good job, man. Now you can securely retrieve and send your mails.