feat: increase message size from 30 to 50 mb gross

this PR allows attachments and videos of about 38 mb net (50 mb gross).

once relays are sufficiently updated, core will pick up the new default
(core currently uses 18 mb only, an old default of non-chatmail-era)

this is quite some boost in quality or video length, roughly a doubling,
which still being reasonably to overall storage
(with this PR we alllow a single message taking up to 1/10th of storage -
when chatmail was started, this was even 1/3rd.
note, that too large files will be deleted, but there will add a pre-message still)

chatmaild/src/chatmaild/config.py

@@ -31,7 +31,7 @@ class Config:
         self.max_user_send_per_minute = int(params.pop("max_user_send_per_minute", 60))
         self.max_user_send_burst_size = int(params.pop("max_user_send_burst_size", 10))
         self.max_mailbox_size = params.pop("max_mailbox_size", "500M")
-        self.max_message_size = int(params.pop("max_message_size", 31457280))
+        self.max_message_size = int(params.pop("max_message_size", 52428800))
         self.delete_mails_after = params.pop("delete_mails_after", "20")
         self.delete_large_after = params.pop("delete_large_after", "7")
         self.delete_inactive_users_after = int(

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

@@ -22,7 +22,7 @@ mail_domain = {mail_domain}
 #max_mailbox_size = 500M
 
 # maximum message size for an e-mail in bytes
-#max_message_size = 31457280
+#max_message_size = 52428800
 
 # days after which mails are unconditionally deleted
 #delete_mails_after = 20

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

@@ -56,6 +56,8 @@ mail_server_admin = mailto:{{ config.privacy_mail }}
 # <https://doc.dovecot.org/2.3/configuration_manual/quota_plugin/>
 mail_plugins = zlib quota
 
+imap_capability = +XDELTAPUSH XCHATMAIL
+
 
 # Authentication for system users.
 passdb {

cmdeploy/src/cmdeploy/tests/online/test_0_login.py

@@ -15,6 +15,13 @@ def test_init(tmp_path, maildomain):
     assert config.mail_domain_bare == maildomain
 
 
+def test_capabilities(imap):
+    imap.connect()
+    capas = imap.conn.capabilities
+    assert "XCHATMAIL" in capas
+    assert "XDELTAPUSH" in capas
+
+
 def test_login_basic_functioning(imap_or_smtp, gencreds, lp):
     """Test a) that an initial login creates a user automatically
     and b) verify we can also login a second time with the same password