Route your Zimbra Collaboration server's outbound mail to the MailGuard relay host, and have it delivered — DKIM-signed — from reputation-managed IP pools. Your inbound mail is cleaned of spam and viruses too.
Zimbra runs a Postfix MTA underneath and usually sends from a single corporate IP. If that IP's reputation, PTR record, or SPF/DKIM alignment is insufficient, mail is delayed or lands in spam. When you configure MailGuard as your relay MTA host, authentication, signing, and reputation management move to MailGuard.
zmprov, set the Relay MTA host to relay.mailguard.com.tr (port 587).zmmtactl restart). MailGuard handles DKIM signing.For detailed, copy-paste configuration, see the docs. To test your domain, use the SPF/DKIM/DMARC tool and mail test.
| MailGuard | Direct from server | Doing nothing | |
|---|---|---|---|
| DKIM signature on outbound mail | Automatic (MailGuard signs) | You have to set it up | None |
| IP reputation management | Fixed, monitored pool per domain | Single IP — everyone shares the same risk | None |
| Inbound spam / virus filtering | Yes (MX redirection) | Depends on the server | None |
| Risk of blacklisting | Minimal (isolated pool) | High | High |
| Delivery visibility / logs | Real-time dashboard + API | Limited | None |
Being able to manage both inbound and outbound email security from a single platform has been a huge convenience.
We can securely manage multiple mail servers from a single point.
We've been using it for a long time. We're especially pleased with the stability and spam protection it provides for enterprise email traffic.
Our users no longer miss important emails. A service that inspires confidence.
The malicious-content filtering on inbound mail works remarkably well.
The number of our emails landing in the spam folder has dropped noticeably. It met our expectations.
Let's discuss your current setup, your volume, and your delivery issues, and put together a migration plan tailored to you.
Get a QuoteZimbra Collaboration is a widely used platform for enterprise email and collaboration. It sends email through the underlying Postfix MTA. Delivery to external providers, however, depends on the server's IP reputation, reverse DNS, and SPF/DKIM/DMARC alignment. If any of these settings is missing, corporate mail can land in spam.
The relay host model hands this complexity off to MailGuard. Instead of sending outbound mail straight to the internet, Zimbra forwards it to MailGuard; MailGuard takes on authentication (DKIM signing), content/virus inspection, and reputation management, and delivers to the destination with correct PTR and HELO. Your organization is freed from the burden of managing the reputation of its single IP.
On the inbound side, pointing your MX record to MailGuard filters out spam, phishing, and viruses before they ever reach your Zimbra server. The result: more stable corporate email traffic, higher deliverability, and inbound/outbound security managed from a single platform.