# Via 1 campaign mail is going and via another showing error **URL:** \ **Category:** Product Support\ **Created:** [May 5, 2021, 3:53pm UTC](https://forum.mautic.org/t/via-1-campaign-mail-is-going-and-via-another-showing-error/19357 "2021-05-05T15:53:44Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![ashishajmani](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/ashishajmani/32/608_2.png) [@ashishajmani](https://forum.mautic.org/u/ashishajmani)\ **Post date:** [May 5, 2021, 3:53pm UTC](https://forum.mautic.org/t/via-1-campaign-mail-is-going-and-via-another-showing-error/19357/1 "2021-05-05T15:53:44Z")
Hello via 1 campaign, my email is going but via another campaign mail is going in error - for same mail acocunt error coming is: "503 Only one sender per message, please " ![image](https://us1.discourse-cdn.com/flex020/uploads/mautic/original/2X/a/a1de6a4892b04e4427cf8210bef083e2503c8c6e.jpeg) any ideas ? Thanks a. ---
**Author:** ![mikew](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/mikew/32/5156_2.png) [@mikew](https://forum.mautic.org/u/mikew)\ **Post date:** [May 5, 2021, 6:31pm UTC](https://forum.mautic.org/t/via-1-campaign-mail-is-going-and-via-another-showing-error/19357/2 "2021-05-05T18:31:10Z")
I am not sure if this is an error you are getting from your ESP or maybe from Mautic. The emails you are sending, are they defined as transactional or marketing ? Marketing emails will only be sent once to each user, hwowver even so you would not be seeing this error. It is giving you Only one sender per message, have you checked the email to make sure that in the advanced section there is only one email defined as the from address ? What ESP are you using and do you have any limitations on it. ---
**Author:** ![ashishajmani](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/ashishajmani/32/608_2.png) [@ashishajmani](https://forum.mautic.org/u/ashishajmani)\ **Post date:** [May 6, 2021, 3:55am UTC](https://forum.mautic.org/t/via-1-campaign-mail-is-going-and-via-another-showing-error/19357/3 "2021-05-06T03:55:07Z")
Hi Mike Few observations & Crux of the issue/resolution: 1. user created with different domain - “u1@domain1” 2. Segment created using this user 3. we are using SMTP of SendGrid 4. campaign run using this segment and user - failed 5. campaign run using different user, with domain2, and using same segment as above - failed 6. i had different domain3 - we verified this domain in SendGrid 7. created user ‘U2@domain3’ and created segment using this user 8. campaign run using this segment and user - Passed 9. campaign run using different user, with domain4, and using same segment as above (7) - PASSED so meaning if we are using any domain in a single instance, it has to get white listed via SMTP provider, atleast with Sendgrid for that matter. thanks a ---
**Author:** ![mikew](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/mikew/32/5156_2.png) [@mikew](https://forum.mautic.org/u/mikew)\ **Post date:** [May 6, 2021, 11:25am UTC](https://forum.mautic.org/t/via-1-campaign-mail-is-going-and-via-another-showing-error/19357/4 "2021-05-06T11:25:20Z")
I think that you should try and use SendGrid API connection instead of SMTP as smtp is set to one sender whereas API you can use multiple senders, you would need to go to Settings (in SendGrid) and authenticate your different domains. ---
**Author:** ![ashishajmani](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/ashishajmani/32/608_2.png) [@ashishajmani](https://forum.mautic.org/u/ashishajmani)\ **Post date:** [May 6, 2021, 11:47am UTC](https://forum.mautic.org/t/via-1-campaign-mail-is-going-and-via-another-showing-error/19357/5 "2021-05-06T11:47:58Z")
So you are saying that via API I can sent multiple senders instead of having with just sendgrid if I take SMTP route ? Thanks a. ---
**Author:** ![joeyk](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/joeyk/32/11164_2.png) [@joeyk](https://forum.mautic.org/u/joeyk)\ **Post date:** [May 6, 2021, 12:27pm UTC](https://forum.mautic.org/t/via-1-campaign-mail-is-going-and-via-another-showing-error/19357/6 "2021-05-06T12:27:01Z")
Did you choose ‘sender is the owner’ in the advanced tab for the email? If so, did you allow domain2 to be a sender at the Sendgrid dashboard? Thx, Joey ---
**Author:** ![ashishajmani](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/ashishajmani/32/608_2.png) [@ashishajmani](https://forum.mautic.org/u/ashishajmani)\ **Post date:** [May 6, 2021, 12:48pm UTC](https://forum.mautic.org/t/via-1-campaign-mail-is-going-and-via-another-showing-error/19357/7 "2021-05-06T12:48:02Z")
I will test it out. Thanks a. ---
**Author:** ![ashishajmani](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/ashishajmani/32/608_2.png) [@ashishajmani](https://forum.mautic.org/u/ashishajmani)\ **Post date:** [May 6, 2021, 3:11pm UTC](https://forum.mautic.org/t/via-1-campaign-mail-is-going-and-via-another-showing-error/19357/8 "2021-05-06T15:11:26Z")
I have tried ‘sender is the owner’ and given From email using u1@domain1 - failed ---
**Author:** ![joeyk](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/joeyk/32/11164_2.png) [@joeyk](https://forum.mautic.org/u/joeyk)\ **Post date:** [May 7, 2021, 5:28am UTC](https://forum.mautic.org/t/via-1-campaign-mail-is-going-and-via-another-showing-error/19357/9 "2021-05-07T05:28:37Z")
Is this domain verified in sendgrid? Dont use sender is the owner. Plz try again just trying to send the email from domain1. ---
**Author:** ![ashishajmani](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/ashishajmani/32/608_2.png) [@ashishajmani](https://forum.mautic.org/u/ashishajmani)\ **Post date:** [May 7, 2021, 6:12am UTC](https://forum.mautic.org/t/via-1-campaign-mail-is-going-and-via-another-showing-error/19357/10 "2021-05-07T06:12:11Z")
not goint…i think without domain approval via SMTP provider, it wont work. ---
**Author:** ![mikew](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/mikew/32/5156_2.png) [@mikew](https://forum.mautic.org/u/mikew)\ **Post date:** [May 7, 2021, 7:10am UTC](https://forum.mautic.org/t/via-1-campaign-mail-is-going-and-via-another-showing-error/19357/11 "2021-05-07T07:10:50Z")
Hey @joeyk I think in SendGrid there are two ways to connect up, one is via smtp and in this way you define what the sender is (and the authentication is done on the specific sender, Sendgrid will send an email to the sender to verify that it is a real address), and then only this is the sender that can deliver e-mails, or via API and here you can authenticate on the domain level and once this is done you can authenticate on multiple domains and use any prefix @domain.com to send e-mails. I think that is why in this specific case the first mailer is being sent without an issue, but on the second mailer from domain2, mautic is passing through [username@domain2.com](mailto:username@domain2.com) and SendGrid is expecting to get [username@domain.com](mailto:username@domain.com) (that is already verified). ---
**Author:** ![ashishajmani](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/ashishajmani/32/608_2.png) [@ashishajmani](https://forum.mautic.org/u/ashishajmani)\ **Post date:** [May 7, 2021, 7:37am UTC](https://forum.mautic.org/t/via-1-campaign-mail-is-going-and-via-another-showing-error/19357/12 "2021-05-07T07:37:11Z")
> [@mikew](#): > > I think in SendGrid there are two ways to connect up, one is via smtp and in this way you define what the sender is (and the authentication is done on the specific sender, Sendgrid will send an email to the sender to verify that it is a real address), and then only this is the sender that can deliver e-mails, or via API and here you can authenticate on the domain level and once this is done you can authenticate on multiple domains and use any prefix @domain.com to send e-mails. > > I think that is why in this specific case the first mailer is being sent without an issue, but on the second mailer from domain2, mautic is passing through [username@domain2.com](mailto:username@domain2.com) and SendGrid is expecting to get [username@domain.com](mailto:username@domain.com) (that is already verified). thats exactly what is happening…so now I am getting domain 2 verified in Send grid and will check and confirm back… happy to see what experts have to say - @joeyk @mikew ---
**Author:** ![ashishajmani](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/ashishajmani/32/608_2.png) [@ashishajmani](https://forum.mautic.org/u/ashishajmani)\ **Post date:** [May 7, 2021, 8:34am UTC](https://forum.mautic.org/t/via-1-campaign-mail-is-going-and-via-another-showing-error/19357/13 "2021-05-07T08:34:03Z")
New case arrived @mikew I verified Domain 3 edited mail template; added From mail using user@domain3 - Mail sent - OK edited mail template; added From mail using user@domain3, Enabled Owner as mailer - FAILED why is that so ? Thanks a ---
**Author:** ![mikew](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/mikew/32/5156_2.png) [@mikew](https://forum.mautic.org/u/mikew)\ **Post date:** [May 7, 2021, 9:41am UTC](https://forum.mautic.org/t/via-1-campaign-mail-is-going-and-via-another-showing-error/19357/14 "2021-05-07T09:41:42Z")
can you please try and connect up using API and not smtp. In SendGrid go and generate yourself an API key and then in mautic choose API connection and put in the API key. Then in SendGrid go and authenticate your domain - you will need to update your DNS records and then try My best is you will happy working after this ---
**Author:** ![mikew](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/mikew/32/5156_2.png) [@mikew](https://forum.mautic.org/u/mikew)\ **Post date:** [May 7, 2021, 9:42am UTC](https://forum.mautic.org/t/via-1-campaign-mail-is-going-and-via-another-showing-error/19357/15 "2021-05-07T09:42:20Z")
are you sending the message as transactional or marketing ---
**Author:** ![ashishajmani](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/ashishajmani/32/608_2.png) [@ashishajmani](https://forum.mautic.org/u/ashishajmani)\ **Post date:** [May 7, 2021, 9:43am UTC](https://forum.mautic.org/t/via-1-campaign-mail-is-going-and-via-another-showing-error/19357/16 "2021-05-07T09:43:12Z")
> [@mikew](#): > > can you please try and connect up using API and not smtp. > > In SendGrid go and generate yourself an API key and then in mautic choose API connection and put in the API key. > > Then in SendGrid go and authenticate your domain - you will need to update your DNS records and then try > > My best is you will happy working after this Sure. I will do that But, my Domain3 is already verified in SendGrid Will working via API will resolve this issue “edited mail template; added From mail using user@domain3, Enabled Owner as mailer - FAILED” - ? ---
**Author:** ![joeyk](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/joeyk/32/11164_2.png) [@joeyk](https://forum.mautic.org/u/joeyk)\ **Post date:** [May 7, 2021, 9:55am UTC](https://forum.mautic.org/t/via-1-campaign-mail-is-going-and-via-another-showing-error/19357/17 "2021-05-07T09:55:32Z")
> [@ashishajmani](#): > > Will working via API will resolve this issue “edited mail template; added From mail using user@domain3, Enabled Owner as mailer - FAILED I’m not sure why you want to set Mailer as owner. Who is the owner of the contact? Do you have many owners? ---
**Author:** ![ashishajmani](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/ashishajmani/32/608_2.png) [@ashishajmani](https://forum.mautic.org/u/ashishajmani)\ **Post date:** [May 7, 2021, 9:57am UTC](https://forum.mautic.org/t/via-1-campaign-mail-is-going-and-via-another-showing-error/19357/18 "2021-05-07T09:57:00Z")
Transactional. ---
**Author:** ![mikew](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/mikew/32/5156_2.png) [@mikew](https://forum.mautic.org/u/mikew)\ **Post date:** [May 7, 2021, 11:10am UTC](https://forum.mautic.org/t/via-1-campaign-mail-is-going-and-via-another-showing-error/19357/19 "2021-05-07T11:10:28Z")
From what I can understand yes this should resolve the issues. Best to go ahead and try. Make sure your domains are verified otherwise you will not be able to send through them, and to re-iterate make sure you are using API connection and not SMTP ---
**Author:** ![ashishajmani](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/ashishajmani/32/608_2.png) [@ashishajmani](https://forum.mautic.org/u/ashishajmani)\ **Post date:** [May 7, 2021, 12:30pm UTC](https://forum.mautic.org/t/via-1-campaign-mail-is-going-and-via-another-showing-error/19357/21 "2021-05-07T12:30:26Z")
I will check how to run campaign via API’s. Thanks a [Next page](https://forum.mautic.org/t/via-1-campaign-mail-is-going-and-via-another-showing-error/19357.md?page=2)