Hey rassilon,
Thank you for reaching out! I'd recommend checking your MyShaw account to ensure your email address is active. From there, please update your password. Then try logging into Webmail to see if you can send and receive emails (send a test email to yourself). Once confirmed that is working properly, you should just need to update the new password with your email client for it to resume working. If it continues to be an issue, your best bet is to touch base with technical support for further assistance.
Cheers,
Tony | Community Mod.