[02/03] "550 5.7.1 Unable to relay for

I am using SMTP Mail..

I am getting this issue

"550 5.7.1 Unable to relay for user.domai.com"

Have any one faced the issue ?

I have added the server name in the Relay of the IIS

This also not done the trick

Hi,

I found some explanation about that issue:

Quote:

---

If you open the properties for your SMTP server under IIS admin, select the Access Tab, and at the bottom, click "Relay", you will see a check-box at the bottom, which is by default selected, saying "Allow all computers which successfully authenticate to relay, regardless of the list above". In my head-scratching to work out the cause of the error, I had mis-read the message as "Allow all users which succ....". The answer therefore was simple, above that check-box on the relay restrictions tab, there is a options dialog which by default Only the list may relay. Simple as adding your server to the list, or selecting All except the list below. The first one is obviously more secure.

---

Hope it helps,

sparrow1

What does IIS have to do with your problem? That message is from the SMTP server. Do your SMTP server support relaying for that domain (or for any domain for that matter)?