Why does nslookup give different mx records for the same domain?

Question

Domain Name System

Good afternoon!

We use MS Exchange Online. We decided to put a Mail Transfer Agent (MTA) from another vendor in front of him so that letters go through additional. inspection at the MTA in terms of security. Changed MX records to point to the new MTA.

As a result, when resolving, DNS returns either old MX records or new ones. This leads to the fact that some of the letters come directly to MS Exchange Online, and some to the MTA.

What could be the reason for this DNS behavior?

Answer 1

Too many tags.
DNS update time can be up to several days. Wait.

Answer 2

If you use popular paid dns hosting with anycast servers around the world and even leave the default TTL (usually 30 minutes for MX), then the record update time is almost everywhere in half an hour and it will fit.

Answer 3

Stump is more cheerful .

Answer 4

I think I will support bobrovskyserg and also choose Pentium.