Configuring IIS to use a Gmail SMTP relay server

Configuring IIS to use a Gmail SMTP relay server

Starting here make sure the IP address is set to “All Unassigned” port 25.

Under “Access” > “Authentication” check Anonymous, leave basic and windows unchecked.

“Access” > “Connection” check “All except the list below” leave it blank.

“Access” > “Relay Restrictions” same, check “Only the list below” and also check “Allow all computers which successfully authenticate to relay, regardless of list above.”

Match message size limits/etc. to below image (or adjust per environment.)

Also match Delivery settings to below (or adjust per environment.)

For “Outbound Security” select Basic Auth + TLS encryption. Account must be provided by customer.

Set “Outbound Connections” to the listed settings or adjust per environment as necessary.

Lastly be sure the fully-qualified domain name is used. If using an IP address here things can get dicey. Set smart host to smtp.gmail.com andUNCHECK the “Attempt direct delivery before sending to smart host.”