Category Archives: Mailserver

Permanently reject a specific email sender address using postfix

Postfix generally accepts all sender addresses. It might be needed in some rare cases to reject one sender addresses for some reason. With postfix, there is the possibility to use the “check_sender_access” to set individual actions per sender address. For the … Continue reading

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Setup amavisd-new with spamassassin and clamav with postfix

In the here described setup, postfix passes the incoming mails on to amavisd-new. There, the emails get checked for viruses and spam. After the email is checked, it is sent back to postfix for its delivery. Continue reading

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Reject individual email address with address extension

With address extension configured in postfix, it is very easy to use new email addresses for every website you register on, but if some website leaks your email, you might receive lots of spam. If the address was an email address configured … Continue reading

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Setup Dovecot with PAM authentication and SSL on CentOS

Dovecot will act as the IMAP server for this setup. If you need POP3, this can also be provided by dovecot, but in this article I’m just going to show how to setup IMAP with SSL to protect the transfer of emails. Installation … Continue reading

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Configure address extension in Postfix

Address extension is one of the features known from GMail but never thought about configuring for your own mail server. I did not think about it for quite some time as i thought it might be complicate to achieve this feature. But I was surprised to see how easy it using postfix. Continue reading

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Harden the SSL configuration of your mailserver

I described in one of my earlier post how to Setup Postfix with SMTP-AUTH and TLS on CentOS. I will follow up on this article describing how to harden the configuration of your mail server related to SSL. Continue reading

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Setup Postfix for multiple domains

If you have postfix configured as your mail server you have most likely configured it for one particular domain. If you have more then one domain, you can configure postfix to handle those as well to receive emails for them. In … Continue reading

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Setup Postfix with SMTP-AUTH and TLS on CentOS

Understanding Postfix Postfix is like a router in a network, just for email traffic. It receives emails from a sender and tries to send them on to their recipient, where the recipient can be the local postfix server or some other … Continue reading

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SPF and multiple domain mailserver

We all hate spam, right? I think you all know the annoying emails, but what is worse than receiving emails? How about when emails you send to someone are for some reason detected as spam? This happened to me recently. … Continue reading

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