I created a distr list in outlook 2007 last year. I used it successfully and today I needed it again. I added a couple of names. I'd say has about 50 names in it. Then every single one came back with this error:
The following message to <'a.org'> was undeliverable.
The reason for the problem:
5.1.2 - Bad destination host "DNS Hard Error looking up rbwm.org' (MX):
Ive taken their email address out so the a@org is not real. I looked up a couple of the email addresses on the websites and they are still the same as last year.
I then took some off the one list and put them on the other. So I have 30 on one and the rest on another and I still get the same problem I can send emails fine but not this distr list which is a pain as I dont wanna write down the addresseses one by 1.
I have not used a distribution list in Outlook for external e-mails, so I am not exactly sure how Outlook 2007 works, however, it is possible that if even ONE of the e-mail addresses is bad, the message will fail to be sent to all addresses. If one in each group is bad, then both groups will fail. Try putting 5 known good addresses into a distribution group to see if that works.