New domain : some emails not reaching sender - am i going mad?

[CapnPugwash]

Hi,

 

This is driving me abit mad...

 

We have an Exchange 2010 server. Our domain WAS oldDomain.county.uk, it's NOW newDomain.county.uk.

 

The company hosting our domains has left both of them live, in three months time oldDomain.county.uk will cease to exist.

 

I've set newDomain.county.uk as the primary address in Exchange. All emails sent to [email protected] & [email protected] are routed to the same mailbox but all replies come from [email protected].

 

Everything was working fine - or so I thought - I'm now getting reports from various users that 'some' emails they are sending to external accounts are not being received.

 

I've checked our IP & domain name - we are not blacklisted. Also one of the external providers a few people are having problems with is Hotmail - I've set up a test Hotmail account and I can email it without issue. I've also had the users with issues email it and they have also had no problem.

 

The issue appears to have no rhyme or reason - the only thing I can think of is that some email providers are seeing emails as having originated from two domains / addresses but the same IP and treating the emails as spam...

 

Can anyone suggest anything for to look at, this is driving me BONKERS!

[round2it]

we are having the same issue

 

our council helpdesk told me that our provider has been blacklisted by microsoft.

 

so all schools using microsoft mail products 365 for example are getting bounced back

 

try sending an email to a google account and they should get through.

[bossman]

We had the same trouble with being blacklisted by Microsoft, those users should be receiving a bounce back e-mail from Microsoft with a link to send asking them to unlist you from their blacklist.

 

It only took 24 hours but they got back to me almost immediately with a response.

 

Good Luck

[CapnPugwash]

Hi, We aren't blacklisted... I can send emails to a Hotmail account I've set up and they all get through OK. I can get other users to email this address & have no issues.

 

I've checked our server IP and domain name in Email Blacklist Check - See if your server is blacklisted & they come back as clean.

 

What seems to be the issue is : if a user has previously emailed an external address from [email protected], when they send that external address an email from [email protected] their email is dumped into the spam folder... this doesn't apply to all external addresses... in some cases it seems random.

 

I'm struggling with this one!

[CapnPugwash]

For anyone interested : This seemed to only affect a few members of staff. With Hotmail, it either resolved itself OR they got the recipient to add the new email address in 'contacts' and that sorted it.

 

One company we deal with had to whitelist our new domain but since then we've had no issues.

 

Bizarre. I have to assume that the domain name change triggered spam filters (in some instances) ... I'm happy it all seems to be resolved but if anyone can explain what might have happened I'd love to know.