Transport suddenly stops working for no apparent reason

Hello,

I have this set up that redirects messages incoming to a certain address over to a PHP script:

"
begin routers

emailing:
  driver    = accept
  domains   = example.com
  transport = transport_script
  condition = ${if eq{$header_to:}{[email protected]}}
  unseen

begin transports

transport_script:
  driver  = pipe
  user    = abc
  group   = abc
  command = "php8.4 index.php"
"

This had been working flawlessly for a few months until this morning when it was brought to my attention that it didn't work anymore. Upon merely restarting Exim the whole thing starts working again. Any idea what might have caused the hiccup?

To provide some more details these are the relevant lines from the log:

- transport in working order:

2025-08-04 17:26:45 1uix5J-00Gal3-1C <= [email protected] H=102b.relay.example2.com [1.2.3.4] P=esmtps X=TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256 CV=no S=278889 DKIM=example2.com [email protected]
2025-08-04 17:26:45 1uix5J-00Gal3-1C => emailing <[email protected]> R=local_user T=maildir_home
2025-08-04 17:26:47 1uix5J-00Gal3-1C => emailing <[email protected]> R=emailing T=transport_script
2025-08-04 17:26:47 1uix5J-00Gal3-1C Completed

- transport NOT in working order:

2025-08-14 06:45:19 1umPq3-0076Ju-1B <= [email protected] H=101d.relay.example2.com [1.2.3.4] P=esmtps X=TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256 CV=no S=432716 DKIM=example2.com [email protected]
2025-08-14 06:45:19 1umPq3-0076Ju-1B => emailing <[email protected]> R=local_user T=maildir_home
2025-08-14 06:45:19 1umPq3-0076Ju-1B Completed

Thanks

Vaclav




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