Meaning of "protocol !indexer-worker"

[Angel L. Mateo]

Hello,

	I'm configuring dovecot 2.2.28. Comparing with previous versions I have 
found now in 10-mail.conf the config:

protocol !indexer-worker {
   # If folder vsize calculation requires opening more than this many 
mails from
   # disk (i.e. mail sizes aren't in cache already), return failure and 
finish
   # the calculation via indexer process. Disabled by default. This 
setting must
   # be 0 for indexer-worker processes.
   #mail_vsize_bg_after_count = 0
}

	I can see that indexer-worker is the index service in dovecot.

	But I don't what the '!' means in front of the service name. Any who 
can explain it to me?

-- 
Angel L. Mateo Martínez
Sección de Telemática
Área de Tecnologías de la Información
y las Comunicaciones Aplicadas (ATICA)
http://www.um.es/atica
Tfo: 868889150
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