outgoing email bounce on gmailserver before 4 days

pihu

my mail cow mail server working fine since 1yr ,but suddenly from 4 days before outgoing all mail to gmail server is fine.
dont know wht problem is arise suddenly. no blacklist was there ptr is fine some time dns not catch so thats why i set premium dns.

domain is mail.medicarrier.co.in ip adress 103.106.194.34
i didnt not know wht is the problem.

this is bounce back msg
host aspmx.l.google.com[74.125.130.27] said: 550-5.7.1
[103.106.194.34 12] Gmail has detected that this message is 550-5.7.1
likely unsolicited mail. To reduce the amount of spam sent to Gmail,
550-5.7.1 this message has been blocked. For more information, go to 550
5.7.1 https://support.google.com/mail/?p=UnsolicitedMessageError
d9443c01a7336-1fd6f478fa0si7170405ad.528 - gsmtp (in reply to end of DATA
command)

i need help desperately pl z help me

esackbauer

Well it is already said in the link that you got with the bounce message.
You could tackle that issue with the postmaster tools from Gmail and maybe set the specific DNS record.

But also:
Unfortunately your IP address is blacklisted on a RBL: dnsbl-3.uceprotect.net
You can check this here.
Only your hoster/ISP can remove you from there, or offer you a new IP address from a proper IP range.

pihu

esackbauer hi can u tell that this blacklist accure any problem with gmail outgoing issue.
also i try to find with postmaster but no luckis there

esackbauer

You also could configure a commercial relay service like mailgun or sendgrid to avoid this problem.

esackbauer

Also your mailcow is presenting the default self signed certificate of mailcow, instead of the Lets Encrypt certificate.

pihu

esackbauer. Hi can u guide me how i setup lets encrypt cirtificate.
bcz our mailserver is working fine but suddenly its not deliverd

esackbauer

https://docs.mailcow.email/post_installation/firststeps-ssl/