If you're having trouble sending mail through us, there are a few things you want to check for.
Are your credentials correct?
The easiest thing to check for is if the username or password are correct. Make sure that you are using your Pobox alias and your proper password for your email application.
Is your SMTP deactivated?
If you log into your account and see this message, then your SMTP is deactivated:
What you will need to do is first change your Pobox password, then contact customer support. We'll turn on your SMTP service after.
Are you using Two Factor Authentication?
If you are using Two Factor Authentication, then you'll want to be sure that you are using an App-specific password for your email application.