postfix-pcre on Ubuntu server

[c***@avantguardsystems.com]

I've discovered that authenticated users can send an email from an address that is not the server's official domain. For example: ***@mydomain.com can have ***@outlook.com put in the From and Return-Path fields. Not good. I have yet to determine whether the user name (in this case 'user') has to be exactly the same or not. Part of the problem may be that I never required users to use the entire address field to authenticate. That is they log in with just 'user' and not '***@mydomain.com'. Maybe that would prevent this issue.
Anyhow, based on research over the web a solution involves installing postfix-pcre. But when I try that it complains that postfix is the wrong version. In this case, postfix is version 3.3.0-1ubuntu0.2: whereas postfix-pcre requires v. 3.3.0-1ubuntu0.1. Maybe this more a question for the Ubuntu team, but has anyone else dealt with this issue?
Or perhaps someone knows a way to solve my problem without postfix-pcre

[Victor d'Agostino]

Hello

Not good, but not so bad ! It's the @Outlook.com mail administrator problem, not yours.

Postfix is a MTA and MTA are not supposed to work on header fields level (although postfix has a built-in content modules like header_checks).

So yes you will need a third party tool or script if you REALLY NEED to ensure the address in the header From field is the same as the SMTP dialog FROM attribute and does not "spoof" an other mail domain.

But if the last MTA enforces SPF, DKIM and DMARC then it will be able detect and block this kind of email with a spoofed domain in the From header field.

Regards
Victor d'Agostino

Post by c***@avantguardsystems.com
Anyhow, based on research over the web a solution involves installing postfix-pcre. But when I try that it complains that postfix is the wrong version. In this case, postfix is version 3.3.0-1ubuntu0.2: whereas postfix-pcre requires v. 3.3.0-1ubuntu0.1. Maybe this more a question for the Ubuntu team, but has anyone else dealt with this issue?
Or perhaps someone knows a way to solve my problem without postfix-pcre