Sender Verification Callouts

[jkook]

Do you guys use 'Sender Verification Callouts' for mail?

 

There are advantages and disadvantages.

What is your experience?

 

Thanks

[ur]

not any more. the advantages should be pretty clear. it checks the local portion of an email, trying to assert the existence of a user @ a domain. but it can be largely unreliable and causes deferrals and can cause excessive backscatter (misdirected bounces).

 

there are many excellent articles on this. just search.

[Lawrence]

What none of the articles mention however, is that there are many broken SMTP servers out there that don't handle these callbacks properly and some even say an address doesn't exist, when it in fact does. I can only assume this is to prevent spam some how.