My client has a 2011 SBS server used mainly for email on "myclient.co.uk" domain. I've been asked to set up some emails for a different domain, let's say "myclient2.co.uk"
So, I've gone into EMC and I've entered "myclient2.co.uk" as an accepted domain (authoratitive) in Hub Transport>Accepted Domains. I've then gone into ADUC and created 4 new users. I've then gone back into EMC and I've created the 4 new mailboxes and linked them to the new users and made sure the new domain email address is the default for each user. I've logged on to OWA as one of the new users and successfully sent an email which I've received in my own email account. I've then gone into the domain control panel for myclient2 with 1and1 and I've created mail.myclient.co.uk and pointed it to the external IP of the mail server and created an MX record pointing to mail. with a pref of 10. When I ping mail.myclient2.co.uk I get the correct IP address come up and MXtoolbox reports everything pointing to the right IP address. However all emails to the new addresses are being bounced almost immediately with "Invalid address" coming from 1and1 mail server.
If this was a DNS propogation delay then surely the ping and MXToolbox would come back from the old 1and1 system rather than from the IP of the server?
Any help gratefully received!