Email Account question

I forward all my Gmail to my Comcast.net account.  I set up eM Client for the Comcast account and mail seems to work ok.  
However, when I create an email with eM Client, it uses my Comcast email address as the FROM address.  I dont want that. I want eM Client to use my GMAIL email address as the FROM address.
Can this be done?

Hello,
Have you entered your two email addresses in eM Client?
Best regards.

No. If I enter the 2nd GMAIL account, will it not try to get emails from GMAIL POP? 
I dont want that.  Just Comcast POP mail, which all my other mail is forwarded to.  Outlook allows for specifying a different REPLY email address in the account settings, which in my case is set to my GMAIL address.  Does eM Client not have this feature.

Are you saying that with eM Client I would stop forwarding to Comcast, and use the two accounts for POP3, and only select my GMAIL account to send emails from eM Client?

Hello Dieter,
I’m afraid that if you need to reply from your gmail account it also needs to be added to eM Client and then for each reply you can choose which address you’re replying from.

Best regards,
Olivia