Email Not Sending: SMTP Troubleshooting

Business email · 5 min read

1. Identify the sending path

Separate messages sent from an email app from WordPress notifications. Record sender, time, recipient and exact error. A form can show success even though the recipient has not received anything.

2. Try webmail

Log into the mailbox’s webmail and send to an external address you can access. If that works, focus on the app settings. If webmail also fails, check quota and give the rejection message to support.

3. Check SMTP

Use the supplied server and port/encryption pairing. The username is the full address and the password belongs to the mailbox. Enable SMTP authentication. Do not disable certificate checks to bypass an error.

4. Read delivery rejection

A non-delivery report may identify an invalid address, quota, attachment or recipient-server refusal. Check the address and try a plain-text message. Server acceptance does not guarantee inbox placement.

5. Review domain and website settings

Have MX and SPF/DKIM authorisations checked for the actual sending service. Do not copy another domain’s values. For WordPress, inspect the sending plugin and logs; a domain-based sender keeps the configuration consistent.

6. Send useful diagnostic details

Provide the domain, time with timezone, full error and checks already made. Remove unnecessary private details. Never send a password or SMTP key in a public form. Avoid repeated retries or bulk mail during diagnosis.