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Email Issues

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#1 CavemanSean


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Posted 25 February 2016 - 05:44 PM

Not to sure if I'm going to be flying over peoples heads here or if I can get assistance with this here... but you won't know until you try... so I'm going to try!



The company I work with runs our own website server (vm3) and we've got 2 companies that have their websites on there (lets call these c1 and c2)


for the longest time, both could email eachother without any issues (they were local accounts so why would there be an issue right?)

Recently C2 decided they wanted to migrate their email hosting to Office 365, so we did that for them, pointed the MX records there, verified email was flowing properly, & disabled 'local host' for email on vm3.


Now here's the issue

C1 goes to email an account that was previously located on vm3 (for example Caveman@c2.ca) they get the following error

Feb 25 16:15:31 vm3 sendmail[28237]: u1PMFVHW028237: ruleset=check_rcpt, arg1=<Caveman@c2.ca>, relay=vm3.c0.ca [XXX.XXX.XXX.XXX], reject=550 5.1.1 <Caveman@c2.ca>... User unknown
Everything I've found thus far on a google search points to users running an exchange server, but we are not... we are running a linux server.

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#2 raw


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Posted 25 February 2016 - 09:21 PM


Recently C2 decided they wanted to migrate their email hosting to Office 365

 Office 365 email is exchange.



 rawcreations.net          @raw_creations

Current systems: WHAT OS, BackTrack-raw, PCLinuxOS, Peppermint OS 6, Kali Linux

and a custom Linux From Scratch server hosting a bunch of top secret stuff.

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