in reply to Re^2: Using Net::SMTP to send pdf attachment
in thread Using Net::SMTP to send pdf attachment

That's quite possible. What does the SMTP server respond when you try? You can instruct Mail::Sender to write the conversation into a log file.

Does your webhost specify any credentials you might use to log in to the SMTP server for sending without these restrictions?

You might try to connect directly the mail server where your mailbox is stored. You may try to

nslookup set type=MX
and use the mail exchanger this displays as the SMTP server to send to your email with a different "From" address. Though the SMTP port may be blocked by your web host.

Enoch was right!
Enjoy the last years of Rome.