This is a big pain for me.

We send a lot of email (actually not that much compared to most companies).

We went through the trouble of setting up a dedicated IP through Sendgrid and getting ReturnPath Certified.

It would fantastic if there was an option for some customers to be able to use their own SMTP for mass emails and to lift or remove the daily sending restrictions.

I don't want my email sending reputation to be shared with other users.

Also, Zoho should really look at signing their Mass Emails with DKIM.  It will be required very soon by some of the big ISPs.

Thanks,

David