Can you offer some information. Are you trying to send all emails from the gmail account to the email.com account ? So all emails get collected in the one email.com account. If yes, then that would be done via the webmail account - server to server. Are you trying to send an email from the gmail account to the email.com account? Do you have a mail account set up in Thunderbird for the gmail account ? Do you have a mail account set up in Thunderbird for the email.com account ? Do you get an error message when attempting to send an email from gmail to email.com? If yes, what is the error message - upload an image file showing the error. Do you have a problem sending any email using the gmail account to any other email address or just to the email.com address ? What OS are you using ? What version of Thunderbird are you using ?