Need urgent help for the use of multiple MX records for Zimbra mail server.

[deshdepak]

I have a domain nicasialaghubitta.com that is currently using the Zimbra mail server MX records with 1000+ email users. I have purchased 15 Microsoft Office 365 Licenses. Now I want to know if it is possible to use the MX record of Office 365 with the MX record of Zimbra to make the flow of emails to the users in Zimbra through MX records of the Zimbra mail server and make the flow of emails to the users in Office 365 through the MX records of Office 365 mail server.

In simpler words, I want to use the multiple MX records of Zimbra and Office 365 mail servers for the same domain name nicasialaghubitta.com. Is this possible? If it's possible, Please help me with the steps to configure this scenario.

[BradC]

Short answer, nope.

How is a sending SMTP server going to know when it looks up the MX for your domain whether the user resides on Zimbra or Office365?

You could do it by putting a third server in front of both Zimbra and Orifice365 and using that to direct the inbound mail, but that's starting to get silly. I know because I did it for a few years, but it wasn't nice.

[deshdepak]

Does this mean that it's not possible to map my use case from the Zimbra mail service side?

[BradC]

https://wiki.zimbra.com/wiki/Split_Domain

[jholder]

Did you open a support case about this? I remember seeing something like that.

Brad is right, the best way to even come close to achieving this is split domain. But the reality is that there may not be a solution for you.