[Fail2ban-users] Adding pattern to postfix filter

[Alex <mys...@gm...>]

Hi,
I'd like to add the following pattern to the postfix filter.

May 30 19:01:42 xavier postfix-116/postscreen[245785]: NOQUEUE: reject:
RCPT from [173.248.144.200]:57963: 550 5.5.1 Protocol error; from=<
web...@my...>, to=<jo...@ex...>, proto=SMTP, helo=<
rdnsb18.mytrueguide.com>

I have a basic understanding of how the postfix.conf filter works. If I'm
correct, I need to modify the mdpr-normal pattern. However, I'm not sure I
understand the difference between mdpr-normal and mdre-normal?

mdpr-normal = (?:\w+: (?:milter-)?reject:|(?:improper command
pipelining|too many errors) after \S+)
mdre-normal=^%(_pref)s from [^[]*\[<HOST>\]%(_port)s: [45][50][04]
[45]\.\d\.\d+ (?:(?:<[^>]*>)?: )?(?:(?:Helo command|(?:Sender|Recipient)
address) rejected: )?(?:Service unavailable|(?:Client host|Command|Data
command) rejected|Relay access denied|(?:Host|Domain) not found|need
fully-qualified hostname|match%(exre-user)s)\b
            ^from [^[]*\[<HOST>\]%(_port)s:?

Ideally, I'd like to not have to modify that regexp and be able to add my
own, much like what appears to be happening with mdre-errors.

Steps on where to go from here would be greatly appreciated.

Thanks,
Alex