SMTP outgoing IP address


I am using IIS vSMTP for sending mail.  

My server has 3 IP addresses on one NIC.

I want to specify which IP address vSMTP should use when it makes it's outgoing connections....anyway to do this?
Who is Participating?
Dave_DietzConnect With a Mentor Commented:
I believe the SMTP service will simply use the first IP address in the binding order to make outbound connections.

Try shifting the binding order and see if that helps.

Dave Dietz
shambhusingh2004Connect With a Mentor Commented:
Yes,You can use/blind other IP in local SMTP to send mails.

Go to IIS.
Select default SMTP virtual server properties.
Select IP address to which you want to use.
The go the Access TAB
Then select relay restration option
ADD IP address.

Warm Regards,

Vipin Gupta

thomp361Author Commented:
Hi Vipin,

My IP addresses are *.81, *.84, *.85

My server uses .81 for outgoing connections but I want vSMTP to use .85 for outgoing connections.

I tried your idea of adding a relay restriction option, I selected .85, and I granted relay to .85

However, when emails get sent they still have .81 in, so it seems that the vSMTP is still using .81 for outgoing connections.

Thanks for the help,
Free Tool: ZipGrep

ZipGrep is a utility that can list and search zip (.war, .ear, .jar, etc) archives for text patterns, without the need to extract the archive's contents.

One of a set of tools we're offering as a way to say thank you for being a part of the community.

thomp361Author Commented:
Hi Dave,

I changed the IP order in the NIC but the box (and vSMTP) still seems to use .81 for outgoing connections....I thought at first that might have done it but it hasn't.
Hi Marc -

I have production server on which mails are relaying from second IP of server.I have following configuration,please confirm with your server configuration :

My SQL IP are : (Primery) (Secondary)

>> Go to IIS :
>> General TAB >> Assigned IP '' & advanced tab >> add IP ''  & port 25.
>> Access TAB
>> Relay tab >> Only the list below >> add IP ''
>> Allow all computers which successfully authenication to relay,regarding above list (check mark)

Warm Regards,

Vipin Gupta

thomp361Author Commented:
Hi Vipin,

That's what I tried to do, setup a relay for .85, but the when email's get sent they still have .81 in the header.

To confirm, I selected .85 on the 'General' tab, then on the 'Access' tab -> relay restrictions -> 'only the list below' -> granted .85

How did you change the order of the IP addresses?

I believe SMTP will use the one that shows up as the first on the list.

Did you restart the service after making the change?

Dave Dietz
thomp361Author Commented:
I changed the order in the NIC settings under "ip addresses" ...turns out that my server provider said I can only use on of my three IP for outgoing connections anways, so getting vSMTP to use a different IP is a moot point now.

Thanks for helping guys, I'll split the points.
All Courses

From novice to tech pro — start learning today.