When does dovecot use sendmail_path?
I'm trying to plug up all the holes where local mail leaves our mail system without a DKIM signature. One avenue is bounce messages.
I wrote a small sendmail wrapper to add DKIM signatures, and defined it as the value for dovecot's sendmail_path. I presume Dovecot invokes this executable when it has to send a send message.
Under what circumstances does this happen? I tried to provoke a mailout by sending messages to recipients with full quotas and permission locked mailbox files, but could not generate any mail back.
Joseph Tam <jtam.home@gmail.com>
You might be able to generate mail back via rejecting email e.g. any email coming with specific address at MTA level such as Postfix/EXIM. Afaik, dovecot doesn't generate mail back when mail box having already exceeded quota limit but just reject the email while MTA can deny the email at SMTP level when it arrives and before getting delivered via LMTP/LDA and generates automatic response with message like 541/550 error to the sender.
Zak.
On 2025-07-26 02:05, Joseph Tam via dovecot wrote:
I'm trying to plug up all the holes where local mail leaves our mail system without a DKIM signature. One avenue is bounce messages.
I wrote a small sendmail wrapper to add DKIM signatures, and defined it as the value for dovecot's sendmail_path. I presume Dovecot invokes this executable when it has to send a send message.
Under what circumstances does this happen? I tried to provoke a mailout by sending messages to recipients with full quotas and permission locked mailbox files, but could not generate any mail back.
Joseph Tam
dovecot mailing list -- dovecot@dovecot.org To unsubscribe send an email to dovecot-leave@dovecot.org
You might be able to generate mail back via rejecting email e.g. any email coming with specific address at MTA level such as Postfix/EXIM. Afaik, dovecot doesn't generate mail back when mail box having already exceeded quota limit but just reject the email while MTA can deny the email at SMTP level when it arrives and before getting delivered via LMTP/LDA and generates automatic response with message like 541/550 error to the sender.
Zak.
On 2025-07-26 02:05, Joseph Tam via dovecot wrote:
I'm trying to plug up all the holes where local mail leaves our mail system without a DKIM signature. One avenue is bounce messages.
I wrote a small sendmail wrapper to add DKIM signatures, and defined it as the value for dovecot's sendmail_path. I presume Dovecot invokes this executable when it has to send a send message.
Under what circumstances does this happen? I tried to provoke a mailout by sending messages to recipients with full quotas and permission locked mailbox files, but could not generate any mail back.
Joseph Tam <jtam.home@gmail.com>
dovecot mailing list -- dovecot@dovecot.org To unsubscribe send an email to dovecot-leave@dovecot.org
participants (2)
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Joseph Tam
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Zakaria