(I don't know whether to submit this to SuperUser or StackOverflow.)

My friend and I have a subscriber list -- strictly opt-in, for people interested when we release new projects -- and we may want to send out a first email this year. How would one best send an email to over 10,000 people? Perhaps there is a good, I suppose paid service, which would do this for one? The key being that the emails ought arrive, with good chances of not being immediately labeled as spam due to the sender or something (as it's definitely not spam). When I simply send emails from my 1&1 server, they often immediately make it into the spam folder, even though when sending the same email through say Google Appspot, it arrives fine.

FWIW, the email addresses are not yet verified (people simply signed up for the list by providing an email, and optionally a name). Analyzing what bounced may be a pro. BTW, we will provide an opt-out link with every mail.

Thanks for any pointers, and sorry if this doesn't fit to ServerFault 100%!