When I am looking for the group list also, it doesn’t show my list. And when I go to the list dashboard, it still doesn’t show the companies unless I clear the filters.
I know I can’t just send my email like this. Is there a proper way in sending group emails to a company-based mailing list?
Emails can only be sent to contact lists, not to company lists. You would have to recreate your list as a contact list for it to appear in the Recipients dropdown.
+1 on @karstenkoehler’s point about the image resolution, just add them as large/original size.
As Karsten said, emails are send to contacts, so you will have to create a contact list. When doing so, you have the option to select company properties of associated companies, see below.