I configured the Phabricator email according to this page: Configuring Inbound Email.

If you don't want Phabricator to take up an entire domain (or subdomain) you can configure a general prefix so you can use a single mailbox to receive mail on. To make use of this set metamta.single-reply-handler-prefix to the prefix of your choice, and Phabricator will prepend this to the 'Reply-To' mail address. This works because everything up to the first (optional) '+' character in an email-address is considered the receiver, and everything after is essentially ignored.

Since I only get one email address for the server, I set the variables metamta.single-reply-handler-prefix and metamta.reply-handler-domain and now it is possible to reply to task as comments and use the email commands.

You can also set up application email addresses to allow users to create application objects via email. For example, you could configure bugs@phabricator.example.com to create a Maniphest task out of any email which is sent to it. To do this, see application settings for a given application at

Can I use the same email address also for creating tasks by email? If so, how can I tell Phabricator to create tasks from this email?

If I now send an email to this email address, I get a reply from Phabricator that it cannot handle this email.

Your email to Phabricator was not processed, because an error occurred while
trying to handle it:

Phabricator can not process this mail because no application knows how to
handle it. Check that the address you sent it to is correct.

(No concrete, enabled subclass of PhabricatorMailReceiver can accept this
mail.)

Thank you for your help.