Frequently asked questions

  • I have purchased PRO, how do I install the full version?

    Please continue to installation page.

  • I am running FREE version and want to upgrade to PRO, how do I do that?

    Please continue to upgrade page.

  • I have forgotten my admin password, what should I do?

    See command-line API.

  • Why do you use single container instead of containers per process?

    There are several reasons for this. It is very easy to distribute by running and updating only one image. We can also guarantee that it will work under all conditions. With more containers it is not so easy. Another reason - running mail server is not that intensive task and usually will not outgrow single server, so we traded full scalability for "ease of use". For larger installations there is an option to separate Antivirus and SpamAssassin, which are the biggest consumers of CPU time. Also, logging, which can get bit-intensive with more traffic, can be offloaded to ElasticSearch.

  • Why SQLite?

    It was a logical choice, as the whole mail server works with files only - emails and settings are files.

    There is no dependency on a running database server. SQLite works with a single database file. The vast majority of queries are SELECTS, writes only happen when you add users, so it has almost no performance penalty over traditional process-based databases. See

  • I am getting "550 Relaying denied" when trying to send email

    SMTP server refuses to process your email because it cannot identify you as a user. The first and recommended option is to use a TLS connection with authentication enabled (port 587 STARTTLS). The second option is to set your IP or subnet as trusted (System settings > Relay settings).

  • Does support tagging like


  • I want use my port 80 for reverse proxy (Nginx)

    Poste only needs to use port 80 for Let's Encrypt authentication, you can easily remap the http port with docker to another if you don't want to use LE. Otherwise you should map the /opt/www/.well-known folder on your web server to /.well-known relative path.

    Example of a special case where you want to use dockered NGiNX with LE Companion and Poste with LE: