zimbra 8.8.6 - some one sending mails using my smtp server

[talluricho]

Hi Team,

I am using zimbra 8.8.6 GA_1906 version and it is working fine upto yestarday but now we are seeing some one using my smtp server and sending bulk mails to yahoo domain.

Please advise how to stop others using my smtp server. i followed below wiki link to stop the unknowbn sender but still no luck, please advise

https://wiki.zimbra.com/wiki/Rejecting_ ... _addresses

[tonster]

Hi Team,

I am using zimbra 8.8.6 GA_1906 version and it is working fine upto yestarday but now we are seeing some one using my smtp server and sending bulk mails to yahoo domain.

Please advise how to stop others using my smtp server. i followed below wiki link to stop the unknowbn sender but still no luck, please advise

https://wiki.zimbra.com/wiki/Rejecting_ ... _addresses

Are you an open relay, or is someones account compromised? You should check to ensure you're not an open relay. Otherwise, you should reset the password or lock the account of whatever account has been compromised.

[talluricho]

sorry for late response. i checked with sophos firewall team to stop smtp relay as I set up a Zimbra mail server behind Sophos.
but it seems we need to change my mail server name from mail.xyzcompany.com to mail.xyzcompany.local to stop smtp relay issue.

Please suggest how to change host name with out losing existing mail ids and SSL certs (as here we are using comodo ssl certificates). Thanks.