> My guess is that individual messages are only stopped when they enter a gmail account That's been tested for and eliminated. My app logs that an email has cr

> My guess is that individual messages are only stopped when they enter a gmail account That's been tested for and eliminated. My app logs that an email has created and is going to be sent. The send_email function is called to send the email. Then my app logs that the email has been sent. The emails are sent to addresses hosted at both gmail and outlook. They are not received. They do not appear in spam bins. GAE has a bounce api that will log if an email is bounced back. In my case, no reports are logged by my bounce handler. The content of my emails has not changed for 2 years. For 2 years both gmail and outlook received my emails in their inboxes (not spam bins). Given all this, I'm pretty sure there is an outgoing spam filter.