Unencrypted E-Mail rejected by SMTP server

[knonem]

Hi,

after setting up S/MIME on my account a couple of weeks ago, today I tried to send an unencrypted e-mail, which was rejected by the SMTP-Server of my e-Mail provider (1&1 IONOS SE).

After asking I got the following explanation from my provider:

"Your e-Mail was rejected by our SMTP-Server, because it does not comply with the defined standards in RFC5321 and RFC5322.
Please make sure, that the e-Mail client fulfills the following criteria when sending an e-Mail:
1. The e-Mail header must have a valid 'date'-field according to RFC2822: (Link to IETF RFC2822, Section 3.3 -> I'm not allowed to post links)
2. The following field may be present only once:  "Date:", "From:", "Sender:", "To:", "CC:", "BCC:", "Subject:"
3. If the field types named above are used, they may not be empty and must be syntactically correct.
Note: The field types „To:“, „CC:“ and „BCC:“ can of course contain several recipients.
We stick to the recommendations out of RFC7103 and to not auto-correct faulty messages, because this will make DKIM-signatures invalid."

I tried several recipients and always got the same error when trying to send an unencrypted e-Mail. When sending an S/MIME encrypted e-Mail however,  it was sent correctly.

Can you look into this?

Thanks

[Anton Donchev]

Hi knonem,

Could you send me an example eml of such message to smime3@mobisystems.com?

Thanks,
Anton.

[peddanet]

I am using OpenPGP with Thunderbird, I am waiting to use this for AquaMail finally? Is this planned, when is it scheduled to be finished?

Thanks in advance, stay healthy!

BR peddanet

[Nedialko Kondev, MobiSystems, AquaMail Support]

Hi,

Sorry but PGP is still not in our development plan. We've not started researching it. We'll be working on S/MIME related issues and user proposals for the following 6-8 months.

When we begin work on PGP, we'll definitely post it here in the forum.

Regards,
Nedialko

[HeikoE]

Hi,

after setting up S/MIME on my account a couple of weeks ago, today I tried to send an unencrypted e-mail, which was rejected by the SMTP-Server of my e-Mail provider (1&1 IONOS SE).

After asking I got the following explanation from my provider:

"Your e-Mail was rejected by our SMTP-Server, because it does not comply with the defined standards in RFC5321 and RFC5322.
Please make sure, that the e-Mail client fulfills the following criteria when sending an e-Mail:
1. The e-Mail header must have a valid 'date'-field according to RFC2822: (Link to IETF RFC2822, Section 3.3 -> I'm not allowed to post links)
2. The following field may be present only once:  "Date:", "From:", "Sender:", "To:", "CC:", "BCC:", "Subject:"
3. If the field types named above are used, they may not be empty and must be syntactically correct.
Note: The field types „To:“, „CC:“ and „BCC:“ can of course contain several recipients.
We stick to the recommendations out of RFC7103 and to not auto-correct faulty messages, because this will make DKIM-signatures invalid."

I tried several recipients and always got the same error when trying to send an unencrypted e-Mail. When sending an S/MIME encrypted e-Mail however,  it was sent correctly.

Can you look into this?

Thanks

I have the same issue, also Ionos, and got the same answer from their side.

[HeikoE]

See the screen shot of the mail in the draft folder.
I couldn't find how to save a draft as eml.

[Martin, Aqua Mail Support]

Hi,

We will log this issue for investigation. @HeikoE - I've e-mailed you from our support channel for some more details that will help us troubleshoot.

Martin