Attachments to emails

@NUNYA -- What are you trying to send? 

I'm taking a stab in the dark with this (because I think I had the same question awhile back) and say your asking about "predefined messages in emails.

In Setup, under Email, you can make templates for emails; can put a subject line, then text in the body. You can specify if the letter is attached as a file, or put into the body of the email (under the template text) etc..

When you go and email a letter in a tenant file, you can use the dropdown "Predefined Messages" menu to use one of the templates you created.

If this isn't what you are asking, just ignore me.