Gmail shows "via" link

rblon · 1 Sep 2011, 08:00 PM

I notice that when I send an email to my gmail account, that Google shows it as:

myname@mydomain.com via messagingengine.com

When I send from myusername@fastmail.fm this "via" doesn't show up.

This suggests somewhat that the sender is not who he says he is. In a sense that is obvious, as you can you use the FastMail SMTP server to send from any email address, but on the other hand, mydomain.com has its MX records pointing to FastMail, so FastMail could give a bit more "reassurance". Or perhaps FastMail should have an option to verify personalities, in order to be able to give "reassurance".

Note that I am not completely sure how the reassurance should be given, but it seems something is possible as the fastmail.fm domain doesn't have this "problem".

neilj · 1 Sep 2011, 08:16 PM

All messages from FastMail are signed with our DKIM key (messagingengine.com). Unfortunately, GMail has decided to equate the DKIM domain with the from address (something it was never intended to do) and show a "via X" label whenever the two are different. They seem to have whitelisted internally all our public domains, but obviously this doesn't work for custom domains. We are working on automatically creating and publishing DKIM keys for custom domains which are hosted with us, so that we can sign the messages with a key corresponding to the domain and thus avoid this problem.

rblon · 1 Sep 2011, 09:12 PM

Thanks for the clear response. Signing with the DKIM key for a FastMail hosted domain only when the email address has been verified (ie that it forwards to the FastMail user) might make sense as well.

neilj · 2 Sep 2011, 02:07 AM

Yes, we will only sign messages from domain X when sent from the user account that owns domain X.

rblon · 2 Sep 2011, 02:48 AM

If domain X is FastMail hosted and the address anotherfmuser@X forwards to another FastMail user, then this user (who doesn't own domain X) should be able to send signed email from anotherfmuser@X, right?

rblon · 2 Sep 2011, 02:51 AM

Also, do you know how Google handles this for their Google Apps users? Do they publish DKIM keys for their customers domains and sign the messages with these keys?

Pfolson · 2 Sep 2011, 06:01 AM

Quote:

Originally Posted by rblon

Also, do you know how Google handles this for their Google Apps users? Do they publish DKIM keys for their customers domains and sign the messages with these keys?

They started providing that feature earlier this year, I believe:

http://www.google.com/support/a/bin/...?answer=174124

Paul

tarun101 · 2 Oct 2020, 01:42 AM

Quote:

Originally Posted by neilj

All messages from FastMail are signed with our DKIM key (messagingengine.com). Unfortunately, GMail has decided to equate the DKIM domain with the from address (something it was never intended to do) and show a "via X" label whenever the two are different. They seem to have whitelisted internally all our public domains, but obviously this doesn't work for custom domains. We are working on automatically creating and publishing DKIM keys for custom domains which are hosted with us, so that we can sign the messages with a key corresponding to the domain and thus avoid this problem.

I think custom domains hosted on fastmail are now signed with DKIM keys but sending identities for which domains are not hosted are not; however in both the cases - gmail (on web) still shows my emails with a “via X” label. What are my options?

1 Sep 2011, 08:00 PM	#1
rblon Essential Contributor Join Date: Jun 2009 Posts: 340	Gmail shows "via" link I notice that when I send an email to my gmail account, that Google shows it as: myname@mydomain.com via messagingengine.com When I send from myusername@fastmail.fm this "via" doesn't show up. This suggests somewhat that the sender is not who he says he is. In a sense that is obvious, as you can you use the FastMail SMTP server to send from any email address, but on the other hand, mydomain.com has its MX records pointing to FastMail, so FastMail could give a bit more "reassurance". Or perhaps FastMail should have an option to verify personalities, in order to be able to give "reassurance". Note that I am not completely sure how the reassurance should be given, but it seems something is possible as the fastmail.fm domain doesn't have this "problem".

1 Sep 2011, 08:16 PM	#2
neilj Cornerstone of the Community Join Date: Apr 2004 Location: Melbourne Posts: 971 Representative of: Fastmail.fm	All messages from FastMail are signed with our DKIM key (messagingengine.com). Unfortunately, GMail has decided to equate the DKIM domain with the from address (something it was never intended to do) and show a "via X" label whenever the two are different. They seem to have whitelisted internally all our public domains, but obviously this doesn't work for custom domains. We are working on automatically creating and publishing DKIM keys for custom domains which are hosted with us, so that we can sign the messages with a key corresponding to the domain and thus avoid this problem.

1 Sep 2011, 09:12 PM	#3
rblon Essential Contributor Join Date: Jun 2009 Posts: 340	Thanks for the clear response. Signing with the DKIM key for a FastMail hosted domain only when the email address has been verified (ie that it forwards to the FastMail user) might make sense as well.

2 Sep 2011, 02:07 AM	#4
neilj Cornerstone of the Community Join Date: Apr 2004 Location: Melbourne Posts: 971 Representative of: Fastmail.fm	Yes, we will only sign messages from domain X when sent from the user account that owns domain X.

2 Sep 2011, 02:48 AM	#5
rblon Essential Contributor Join Date: Jun 2009 Posts: 340	If domain X is FastMail hosted and the address anotherfmuser@X forwards to another FastMail user, then this user (who doesn't own domain X) should be able to send signed email from anotherfmuser@X, right?

2 Sep 2011, 02:51 AM	#6
rblon Essential Contributor Join Date: Jun 2009 Posts: 340	Also, do you know how Google handles this for their Google Apps users? Do they publish DKIM keys for their customers domains and sign the messages with these keys?