SendGrid SMTP API: Multiple e-mails to the same recipient

Question

I have a web app that uses SendGrid's X-SMTP functionality to construct a single e-mail that is then merged and forwarded to a list of recipients specified in the X-SMTPAPI header.

Documentation here: http://sendgrid.com/docs/API_Reference/SMTP_API/

I am using MVC.NET and sending the e-mail using a MailMessage object via smtp.sendgrid.net

Everything seems to be working fine as far as merging values from the header and sending out the e-mails is concerned.

However I have noticed that if I specify the same e-mail address multiple times in the "to" list, only a single e-mail is sent out (or at least I just receive the one).

Has anybody had the same experience? Anybody know of a way to get around this issue?

Thanks in advance!

Answer 1

SendGrid's servers will de-dupe the To array. The only way to get around this is to split duplicates into separate SMTP messages, or to change the addresses so they are not duplicates (you could use plus addressing, e.g. person@example.com and person+foo@example.com).