If you are unable to send and receive emails using your 123-mail address, have a look at this video to find out why that is and how you can solve the issue.
First you will need to determine whether there are issues with our ‘123-mail’ webmail client or with your 3rd party email client. To check this, all you need to do is send and receive a test email using your email account on 123-reg webmail, and then using your 3rd party email client.
For more information on how to solve issues related to sending and receiving emails, go to 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.