Sending an email to a large user base?

[oneguy]

I recently purchased a site with a large userbase. (large for me, anyway, about 7,000 users.)

I've migrated the database to a new and more fitting domain name, along with a ton of new features.

On the old domain name, I have a link to the new site. I plan to discontinue the old domain as quickly as possible. (Please don't ask why. There's nothing shady going on, but it should be done.)

How should I email the userbase and let them know that the site is switching domains. I'm fine with emailing from either domain, but I think it makes sense to email from the original domain.

I can export all of the email addresses into whatever I like, but what to do with them? I'm also thinking such a mailing should be staggered so I'm not eating up too much system resources. I want everyone to get one email, and nobody to get two emails because I flubbed the first try.

I can be can-spam compliant, only emailing the userbase that has opted-in for the domain I purchased, but I still want to try to avoid the appearance of spam. (socially and technically)

[rogerd]

For a one-off, 7K mailing, I wouldn't agonize too much. Send it from the domain they subscribed to, and title it "Important Change to Your Widget Forum Membership" to remind them that they signed up at one time. You might also state near the end that it's a one-time mailing and that they won't be contacted again to assuage the spam nuts.

[oneguy]

Thanks.

It is a one time mailing. The system kicks out messages here and there when certain actions happen, but I have no plans sending other emails unless something giant were to happen.

[Optin]

Is a mailing necessary - if you're 301ing the old site to the new, a front page announcement would be seen by all.
Of course, a mailshot would act as an advertisement to entice members back.

[oneguy]

You're right. That would normally do. But, I've made a decision to ditch the domain entirely. It's a potential liability (IMO) to keep it or continue using it.