[SOLVED] Mail malfunction

Well... I think I made it, eventually.
The problem is in the "From" address: in the case of the "Send a message via email to..." form it leads the receiving mail server to consider the message as spam, while when sending mails from the mass mailer function everything goes well.
Please have a look at the attachments: in the "spam" files you can see that the message doesn't meet the DMARC requirements.
To solve the issue: is it possible to take out from the "From" address the first part? In my case the first part is "MSpina @ GCVPCM", which in any case is present in the body of the message.
Thanks!
Marco

I just checked our CB mailer and phpmailer code, and, as also visible in your images, the "From" name is correctly quoted with double-quotes " " when it contains the @ sign, which is not part of the allowed unquoted characters.

I also checked RFC 7489 (DMARC) and that "from name" part is/should be ignored, only taking in account the email address itself.

DMARC *can* fail if SPF or DKIM fail, and in your cases, the SPF is failing. Can you adjust the SPF record for your "from" domain to allow the IP addresses from which your emails are sending and retry ?

EDIT:
If it still fails DMARC after passing SPF and DKIM, please also provide raw mail header for better analysis of the issue. You can use the CONFIDENTIAL markup with brackets [] around the header in your post if there are private/confidential information.

Did you read the text files attached? They are the raw messages you're asking for.
There you can see:

1. the SPF fail message appears in the messagge successfully delivered, so, it's just a warning, I guess
2. the DMARC fail message instead appears only in the mail marked as spam

The only striking difference between the message refused and the other one is the From field:

• blocked: "MSpina @ GCVPCM" <marco.spina [at] protonmail.com>¹
• accepted: GCVPCM Iscriviti <admin [at] protezionecivilemonza.it>¹

For a developer (I am not) it should be not a great deal trying some small modifications, what do you think?
I repeat myself, the first part ("MSpina @ GCVPCM") is not necessary, since it appears anyway in the body of the message:
***** This is a message from MSpina at GCVPCM (https:// www. protezionecivilemonza. it)¹ to you: ******
Messaggio privato da Live
***** NOTES: ******........[hr]
¹ altered since I'm not allowed to include links; see the text files

You're trying to send emails from your users email address. This isn't allowed most of the time. Within CB > Configuration > General change "Emails Sent From" to "Admin Email Address, with Reply-To User Email Address" as it's likely set to "User Email Address" and is why those emails are being marked spam.

I am using the CB form "Send a message via email to...". And it doesn't work, at least for my site. Full stop.
If a smoking gun isn't enough for you please close this ticket, I will find some workaround.
Many thanks for your time.

The profile email form uses the parameter I described above. Within CB > Configuration > General what do you have "Emails Sent From" set to? Based off the information you provided above it's set to "User Email Address". Change it to "Admin Email Address, with Reply-To User Email Address" and retry.

No idea what you mean by "close this ticket". This is just a forum topic. There is no ticket and this isn't closed.