Sender IP blocked

haiopaii

Hey,
my parents aren´t able to send out mails from my mailcow.
They get blocked because their IP is blocked by spamhaus. ISP is Telekom.
Trying to get a new IP hasn´t resolved the problem.
Any suggestions on how to unblock it in mailcow?

NOQUEUE: reject: RCPT from [XXX.XXX.XXX.XXX]:58054: 550 5.7.1 Service unavailable; client [XXX.XXX.XXX.XXX] blocked using zen.spamhaus.org; from=xxx@xxx.xxx, to=xxx@xxx.xxx, proto=ESMTP, helo=<smtpclient.apple>

DerLinkman

haiopaii they do have a Static IP didn’t they?

pkernstock

What port are they using for SMTP? Are SMTP credentials set in the email client?

haiopaii

hey,

465 is set with correct credentials

aaronsmith

Seems you have only 2 options:

Explicitly whitelist your parent’s ISP CIDR block.
Contact Spamhaus to get more information on being listed. Maybe their machines have been compromised and are part of a botnet? Or the ISP’s CIDR block has been listed for similar reasons.