If you are having trouble sending and receiving email, watch this video to see if maybe this is caused by incorrect authentication settings in your 3rd party email client.
Check the outgoing settings section in your 3rd party email client to see if maybe you have accidentally disabled the authentication option. Depending on which email client you are using, this option could read something like “authenticate using password” or “my outgoing server (SMTP) requires authentication”.
You will need to ensure that this option is enabled and that you are using a password to authenticate email being sent from your account.
Once you’ve made these changes, simply restart your email client and try sending and receiving a test email to ensure it’s working.
For complete steps on how to check and change these settings, watch this video or read our support article here: https://www.123-reg.co.uk/support/answers/Video/Email/having-trouble-sending-and-receiving-emails-4110/
Publisher: 123 Reg
You can watch this video also at the source.