add imap_compress option to chatmail.ini

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## untagged
 
+- Add imap_compress option to chatmail.ini (#760)
+
 - Remove echobot from relays 
   ([#753](https://github.com/chatmail/relay/pull/753))
 

chatmaild/src/chatmaild/config.py

@@ -44,6 +44,7 @@ def __init__(self, inipath, params):
         self.disable_ipv6 = params.get("disable_ipv6", "false").lower() == "true"
         self.acme_email = params.get("acme_email", "")
         self.imap_rawlog = params.get("imap_rawlog", "false").lower() == "true"
+        self.imap_compress = params.get("imap_compress", "false").lower() == "true"
         if "iroh_relay" not in params:
             self.iroh_relay = "https://" + params["mail_domain"]
             self.enable_iroh_relay = True

chatmaild/src/chatmaild/ini/chatmail.ini.f

@@ -99,6 +99,12 @@
 # so use this option with caution on production servers. 
 imap_rawlog = false 
 
+# set to true if you want to enable the IMAP COMPRESS Extension,
+# which allows IMAP connections to be efficiently compressed.
+# WARNING: Enabling this makes it impossible to hibernate IMAP
+# processes which will result in much higher memory/RAM usage.
+imap_compress = false
+
 
 #
 # Privacy Policy

cmdeploy/src/cmdeploy/dovecot/dovecot.conf.j2

@@ -113,7 +113,7 @@ mail_attribute_dict = proxy:/run/chatmail-metadata/metadata.socket:metadata
 # `imap_zlib` enables IMAP COMPRESS (RFC 4978).
 # <https://datatracker.ietf.org/doc/html/rfc4978.html>
 protocol imap {
-  mail_plugins = $mail_plugins imap_zlib imap_quota last_login
+  mail_plugins = $mail_plugins imap_quota last_login {% if config.imap_compress %}imap_zlib{% endif %}
   imap_metadata = yes
 }
 
@@ -252,3 +252,28 @@ protocol imap {
   rawlog_dir = %h 
 } 
 {% endif %}
+
+{% if not config.imap_compress %}
+# Hibernate IDLE users to save memory and CPU resources
+# NOTE: this will have no effect if imap_zlib plugin is used
+imap_hibernate_timeout = 30s
+service imap {
+  # Note that this change will allow any process running as
+  # $default_internal_user (dovecot) to access mails as any other user.
+  # This may be insecure in some installations, which is why this isn't
+  # done by default.
+  unix_listener imap-master {
+    user = $default_internal_user
+  }
+}
+# The following is the default already in v2.3.1+:
+service imap {
+  extra_groups = $default_internal_group
+}
+service imap-hibernate {
+  unix_listener imap-hibernate {
+    mode = 0660
+    group = $default_internal_group
+  }
+}
+{% endif %}