Problem Sending Mass Emails

[noppid]

How are you sending mail? PHP or SMTP? Are you sending mail in batches-delayed or immediate?

If you are using php, have you experimented with the -f option? Does your host allow php mail?

If it's SMTP, is the user name correct and the password correct? Do you have to have a user name or full email address there? Is "SMTP Secure Connection" checked and shouldn't be?

It's a good idea to use the same email address is all three places you can set an email address in vB IMO.