I cant send email to specific domain, 554 5.7.1 Spam message rejected (in reply to end of DATA command))

[fego91]

Hi every body.
I have a problem when i try send email to specific domain, in the log i see this

to=<henrique.bernardes@ciber.com.br>, relay=mx01.wirtgen-group.com[93.122.82.33]:25, delay=3.3, delays=0.05/0/2.2/1, dsn=5.7.1, status=bounced (host mx01.wirtgen-group.com[93.122.82.33] said: 554 5.7.1 Spam message rejected (in reply to end of DATA command))

Anyone can help me please?

 

[BobhWasatch]

The other server is rejecting your email. You might have ended up on one of the various DNS block lists. I had that happen once because someone else in the same IP block at my hosting provider was spamming.

You need to find out which lists you are on and how to get removed. Here is a site that checks several such lists:

https://www.dnsbl.info

ETA: Posting in the Mail Gateway group might get you more help.

 

[Ramalama]

Mailserver:
- Do you have a static ip? Dynamic = spam
- ptr record of the ip should point to the mailserver (mx.yourdomain.com). If it doesn't, chances are high that you land on spamlists.
- spf, optional, but decreases chances to land on spamlists
- mailserver should send over smtps with a trusted certificate (letsencrypt does it)
- don't send html mails, only plain text if possible.
- dkim, optional, good to have, not necessary
- dnssec, optional, not neccessary

Check if your mailserver is on any blacklists and remove it.
You can get an subscription from uribl (costs around 900usd/year), additional to their subscribers antispam list, that you can add to postfix blacklists, they won't block your mailserver ip. (They are the biggest and every other blacklist basically check against them)
I hate uribl for that xD

However, the first 2 points are the most important ones.
This whole reply is based on importance, the first things are most important.

Cheers