i can't send outgoing messages through my gmail account when when switched to iCloud they send

Greetings vermjenna,

Welcome to the Apple Support Communities!

I understand that you are unable to send email from your Gmail account on your Mac. To troubleshoot this issue, I would recommend reading over and working through the suggested troubleshooting steps located in the attached article.

If you can’t send or receive email on your Mac - Apple Support

Cheers,

Joe