I run Zimbra with my own 3 domains since a couple of months. So far, all mail was relayed through the SMTP servers from my ISP. Since this Friday, my ISP does no more allow senders from non-ISP domains to relay through their SMTP server.
Therefore, I sent e-mails straight from Zimbra without relay. Unfortunately, the first e-mail I sent was rejected by the recipient server based on their anti spam defense:
As my ISP now uses gmail, I tried to relay e-mail through google's smtp server. Mail gets delivered. However, the sender's e-mail address is exchanged with the account used to authenticate. Therefore, any response to such e-mail go back to gmail instead of the origin. Therefore, gmail is not an option.
<email@example.com>: host xxx.recipient.com[999.999.999.999] said: 550
5.7.1 <firstname.lastname@example.org>... Mail from 18.104.22.168 refused by RBL,
RSS, or DUL, please see www.mail-abuse.com, sender is email@example.com (in
reply to RCPT TO command)
What is the proper approach to configure Zimbra and other tools so mail is not refused by RBL, RSS or DUL?
- I have a dynamic IP address, owned by my ISP
- Mail is mainly processed by local mail clients