Below is help on configuring Office 365, as an SMTP server, to work with SmartPOP2Exchange.
Office 365 SMTP Relay Connector
To ensure smooth collaboration between Office 365 and SmartPOP2Exchange, you need to configure a connector on the Office 365 to send emails with Office 365 SMTP relay.
Please see the following link for detailed instructions from Microsoft: Configuring a Connector to Send Emails with Office 365 SMTP Relay.
Summary of configuration:
1. Determine the public (static) IP address from which SmartPOP2Exchange will operate. A dynamic IP address is not supported.
2.Select Domains and make sure your domain is enabled and determine the MX record for your domain under Manage DNS.
3.In Office 365, open the Exchange Admin Center. Under Message Flow -> Connectors, create a new connector using the IP address determined from step 1 as the IP address of the sender server.
4.Update your DNS record on the domain registrar website if necessary.
5.In SmartPOP2Exchange, enter the POINTS TO ADDRESS value of the MX record from step 2 as the SMTP/Exchange server.
This is only a rough summary of the full configuration. For detailed information please visit the Microsoft help website linked above.
Please make sure that the connector you use for communication between the Exchange server and SmartPOP2Exchange or the Exchange Server Toolbox allows outgoing emails. Otherwise, your Exchange Server will automatically reject all outgoing messages sent to external recipients.
One source which may cause this problem are the ClamAV mirror servers. To solve the problem, please delete the following file:
Another problem might be caused by the Windows Defender. Add the following paths to the exclusions:C:\ProgramData\JAM Software\ClamAVInABox\SignaturesC:\Program Files (x86)\Common Files\JAMSoftware\ClamAVInABox\sanesecuritydbtemp
This error message is caused by your Exchange Server and no problem of SmartPOP2Exchange.
Your Exchange Server also includes a simple spam filter module called imf. This one refuses messages detected as spam by default.
Because of this SmartPOP2Exchange saves the email and creates that notification message which is send to the user instead to avoid mail loss.
To solve the problem you need to change the behavior of the Exchange Server and make it accept any message from SmartPOP2Exchange.
You either should disable the content filter and sender filter of your Exchange Server or at least change the action to quarantine instead of refusing.
Please configure your Exchange Server to accept any message from SmartPOP2Exchange. Please note that messages in your POP3/IMAP account already count as finally delivered and because of this the behavior of refusing messages by the Exchange Server is similar to their deletion. If that is your intention we recommend you configure your Exchange Server to delete the messages or move them into quarantine. This avoids the error messages in the log of SmartPOP2Exchange and multiple delivery attempts.