Hello,
Did you get the error "554 Sending address not accepted due to spam filter" ?
This is a tricky error that can be difficult to troubleshoot, but you can start by trying the following:
- Verify that your sending IP address and domain name are not on any blacklists
- Verify that you have a valid and correctly formatted SPF record
- Check your outgoing mail server logs for signs of abuse
- Try calling the person you are trying to reach and get a more specific error for the error from their mail support
A useful tool for checking your blacklist status -
Email Blacklist Check - See if your server is blacklisted
Check your IP reputation sender score here -
https://senderscore.org/