DualBoot wrote:Block all except and monitor :
- 25 (SMTP, SMTP with auth)
- 587 (Submission)
- 22 (if need to access your server from the outside world, better use VPN or allow identified IP with private key)
- 110 (POP)
- 995 (POPS)
- 143 (IMAP)
- 993 (IMAPS)
- 80 (HTTP)
- 443 (HTTPS)
That should be enough
Regards
FWIW, and as a suggestion for those new to Zimbra, I typically do not open 110 and 143, as keeping those ports closed forces users to use POPS and IMAPS, and prevents their username:passwords from being transmitted in clear text across the wire.
All the best,
Mark