Send Email | From address must match authenticated address

I am trying out a new web host and most of it's going well, however I am having an issue with sending emails.
When I send an email, I get the following error message:
System.Net.Mail.SmtpException: Mailbox unavailable. The server response was: From address must match authenticated address
Asked the host about this, and yes, to prevent spam, they require the from email address to be the same as the SMTP authentication account used in the Web.Config.
My question is, are there other alternatives?  My problem is that many times there are sub sections of the website that I would like to send from different email accounts. 
Any suggestions?

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