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Can sent from one account but not another with the same SMTP

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Hi all;

I'm running Thunderbird 78.6.0 (32-bit), Windows 10.

I have two accounts on a domain, call them primary@domain.com and secondary@domain.com. This domain does not have an SMTP server.

I have a third account on a commercial service - Mailbox.org - call it account@mailbox.org.

In the Outgoing SMTP server section of Account Settings, I've set up the Mailbox.org SMTP as the server, with the account@mailbox.org login settings.

Both account primary@domain.com and secondary@domain.com have "Outgoing Server (SMTP)" pointing to that default "Mailbox.org (SMTP)"

When I send as account@mailbox.org, it sents without problem.

When I send as user primary@domain.com, it sends without problem.

When I send as user secondary@domain.com, it fails with "<secondary@domain.com> Sender address rejected".

The thing is, all three point to the same SMTP server, with the same SMTP credentials. I've deleted the password and reset it, with no difference.

For some reason, when using primary@domain, the SMTP server uses the stored account@mailbox.org settings, as it should. But when using secondary@domain, somehow the SMTP server is ignoring those credentials. I don't see any configuration differences between primary and secondary.

In Thunderbird, account primary@domain.com has the outgoing SMTP server configured to use the account@mailbox.org account's credentials. I can't see how primary and secondary are any different, other than one works, and the other doesn't.

I've duplicated the SMTP settings to an SMTP2 server, with the same result. The primary can always send, but the secondary cannot.

This is probably something simple, and some setting somewhere, but I can't find it.

Hi all; I'm running Thunderbird 78.6.0 (32-bit), Windows 10. I have two accounts on a domain, call them primary@domain.com and secondary@domain.com. This domain does not have an SMTP server. I have a third account on a commercial service - Mailbox.org - call it account@mailbox.org. In the Outgoing SMTP server section of Account Settings, I've set up the Mailbox.org SMTP as the server, with the account@mailbox.org login settings. Both account primary@domain.com and secondary@domain.com have "Outgoing Server (SMTP)" pointing to that default "Mailbox.org (SMTP)" When I send as account@mailbox.org, it sents without problem. When I send as user primary@domain.com, it sends without problem. When I send as user secondary@domain.com, it fails with "<secondary@domain.com> Sender address rejected". The thing is, all three point to the same SMTP server, with the same SMTP credentials. I've deleted the password and reset it, with no difference. For some reason, when using primary@domain, the SMTP server uses the stored account@mailbox.org settings, as it should. But when using secondary@domain, somehow the SMTP server is ignoring those credentials. I don't see any configuration differences between primary and secondary. In Thunderbird, account primary@domain.com has the outgoing SMTP server configured to use the account@mailbox.org account's credentials. I can't see how primary and secondary are any different, other than one works, and the other doesn't. I've duplicated the SMTP settings to an SMTP2 server, with the same result. The primary can always send, but the secondary cannot. This is probably something simple, and some setting somewhere, but I can't find it.

Chosen solution

Bill de Haan said

So I guess the question isn't really why the secondary worked, but how the primary email works in the first place?

That's a question for the Mailbox.org folks to answer. Thunderbird has zero influence over what is permitted or rejected on the provider's side.

Read this answer in context 👍 0

All Replies (7)

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have you checked the settings in mailbox.org that you have registered secondary@domain.com as a permitted sending email address. My guess is not so they are not allowing it.

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Matt said

have you checked the settings in mailbox.org that you have registered secondary@domain.com as a permitted sending email address. My guess is not so they are not allowing it.

Hi Matt;

There are no settings in Mailbox.org to set. They don't allow any secondary domains. That's why it's configured in Thunderbird to log in as the account@mailbox.org account when sending.

In Thunderbird, the settings log in to the SMTP Server section are:

Connection Security: SSL/TLS Authentication method: Normal Password User Name: account@mailbox.org

When sending from primary@domain.com, it correctly uses the account@mailbox.org credentials. When sending from secondary@domain.com, it doesn't.

That's the thing. Other than their name and password, I can't see anything anywhere that differentiates primary and secondary. I never configured Mailbox.org, and the same SMTP credentials for Thunderbird are used by both primary and secondary. One works, the other doesn't.

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Mailbox would need to know about all the email addresses. https://kb.mailbox.org/display/MBOKBEN/Using+e-mail+addresses+of+your+domain

When I send as user secondary@domain.com, it fails with "<secondary@domain.com> Sender address rejected". https://kb.mailbox.org/display/MBOKBEN/Sending+e-mails+with+non-registered+mailaddresses+-+Sender+address+rejected+not+owned+by+user

Modified by Toad-Hall

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Toad-Hall said

Mailbox would need to know about all the email addresses. https://kb.mailbox.org/display/MBOKBEN/Using+e-mail+addresses+of+your+domain

Thanks.

But now, I'm even *more* confused. I never configured Mailbox.org to send from primary in the first place. My domain's DNS hasn't changed in years.

So I guess the question isn't why isn't secondary working, but how is primary working?

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Toad-Hall said

Mailbox would need to know about all the email addresses. https://kb.mailbox.org/display/MBOKBEN/Using+e-mail+addresses+of+your+domain

Thanks. But now I'm even more confused.

I never configured Mailbox.org with primary, and my domain's DNS hasn't been changed since before I started using Mailbox.

So I guess the question isn't really why the secondary worked, but how the primary email works in the first place?

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Chosen Solution

Bill de Haan said

So I guess the question isn't really why the secondary worked, but how the primary email works in the first place?

That's a question for the Mailbox.org folks to answer. Thunderbird has zero influence over what is permitted or rejected on the provider's side.

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Stans said

That's a question for the Mailbox.org folks to answer. Thunderbird has zero influence over what is permitted or rejected on the provider's side.

Yes, that's fair enough. I'll follow up with them.