[CompassLord]

You can't do it without some sort of password (as far as I know of) as the SMTP requires a sender and receiver email.

You need the password so it can verify that you own the "sender" email

[Malware]

Thank you for responding as quickly. :)dropoff window
I do not understand why we could not, because on the Internet there are anonymous mesh generators. I would do the same thing but in visual basic.
For example, www.anonymousemail.me, this site offers beautiful and many sent an anonymous email or distort the sender. Are you sure that there will not have means to do the same with visual basic ?

Because they have their own SMTP server. The passwords are just in the php code.

You are using gmails or someone elses which requires authentication.