Troubleshooting

Before taking your configuration apart, check what the server actually answers: our online SMTP test opens a real connection and hands back the full transcript.

The two faults that come up most often: a message refused by the recipient’s server, decoded with the error codes for undelivered messages, and a multifunction copier whose scan to email has stopped working with Office 365, where the cause is nearly always authentication rather than the device.

An e-mail message with an attachment is sent repeatedly to recipients Fix an Outlook message with a large attachment that keeps resending to recipients: raise the server connection time limit or compress the attached file.
Analyze error codes for undelivered messages Understand SMTP error codes for undelivered messages in your Service-SMTP reports: wrong address, recipient server issues, SPF failures, and spam rejections.
Scan to email is not working with Office 365 Your copier returns 535 5.7.139 basic authentication is disabled? The three real causes, the immediate fix, and every lasting option compared.