Differences

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--- mail [2012/05/30 21:31] – mb
+++ mail [2019/09/29 15:34] (current) – [account creation] mb
@@ Line 2: / Line 2: @@
 marmot provides a multi-domain IMAP/SMTP mail service, powered by [[http://www.exim.org/|Exim]] and [[http://www.cyrusimap.org/|Cyrus IMAP]].
-It doesn't use SSL, partly because of the paying-for-a-server-certificate issue, and partly because of the multi-domain-but-one-IP-address issue.
 All IPC with backend services (spamd, clamd, pgsql, lmtpd) is performed over unix domain sockets.
@@ Line 18: / Line 16: @@
 This is really a side-effect of the features' original design, to minimise the latency of user delete operations.
+For example, to undelete everything you have expunged today, run the following as the ''cyrus'' user...
+    cyrus@marmot:/$ /usr/lib/cyrus/bin/unexpunge -t1d user/me@jamie.lentin.co.uk
+    restoring expunged messages in mailbox 'jamie.lentin.co.uk!user.me'
+    restored 297 expunged messages
 ===== webmail =====
 [[http://webmail.wormnet.eu/]] ([[http://mebwail.wormnet.eu/]] might work if you're stuck behind a stoopid web filter). It uses HTTP Digest authentication, which is reasonably secure (although Basic auth could be spoofed by a MITM), but logging out can be a bit of a pain since browsers tend not to want to forget your credentials--so please consider this service beta at best.
+The HTTP Digest authentication is backed by PostgreSQL; if you restart the database (eg for a security update) you'll need to do an ''/etc/init.d/apache2 graceful'' at the bare minimum for webmail to continue to work.
 ===== server-side filtering =====
@@ Line 47: / Line 53: @@
 If it's a new domain, please add it to the ''loginrealms'' line in ''/etc/imapd.conf'' on marmot.
-Then use ''cyradm -u cyrus localhost'' on marmot (password in aformentioned ''shadow'' table) and issue "''cm user/username@domain''". Then set an appropriate quota, eg ''sq user/username@domain 100000''.
+Then use ''cyradm -u cyrus localhost'' on marmot (password in aformentioned ''shadow'' table) and issue "''cm user/username@domain''". Then set an appropriate quota, eg ''sq user/username@domain STORAGE 100000''.
+==== shared mailboxes ====
+A mailbox which does //not// begin ''user/'' is not in an INBOX, but a shared mailbox. You can create them in ''cyradm'' with ''cm'', as above, then use ''sam'' and ''lam'' to set and view appropriate permissions, eg:
+  localhost> lam admin/postmaster@wormnet.eu
+  anyone p
+  lentinj@wormnet.eu lrswipkxtecd
+  mb@wormnet.eu lrswipkxtecd
+If, as in this example, you set ''anyone p'', then Exim will deliver straight into that mailbox with e-mail address ''+admin/postmaster@wormnet.eu''.
 ===== aliases/forwarding =====
@@ Line 64: / Line 81: @@
 Malware is rejected at SMTP time; a suitable SpamAssassin score (currently 5.0) will cause a rejection too. So will a dodgy attachment extension, or more general MIME-corruptness. However, even after a 550 after the DATA phase, Exim can store the message somewhere. This allows us to examine mail we've rejected :)
+==== SpamAssassin Bayesian classifier training folders ====
+Please note these as their filesystem locations below, suitable for cutting & pasting. Please ensure that ham folders //only// contain ham, and spam folders //only// spam. If you put something in the wrong folder, please delete it, expunge it and then ask postmaster to purge the expunged files.
+=== ham ===
+  sa-learn --ham --progress /var/spool/cyrus/mail/domain/j/jamie.lentin.co.uk/m/user/me/{archive,projects/*}/*.
+=== spam ===
+  sa-learn --spam --progress /var/spool/cyrus/mail/domain/d/digriz.org.uk/a/user/alex/\:spam/*.
+  sa-learn --spam --progress /var/spool/cyrus/mail/domain/w/wormnet.eu/r/admin/rejected/malware/*.
+  sa-learn --spam --progress /var/spool/cyrus/mail/domain/j/jamie.lentin.co.uk/m/user/me/spam/*.
+  sa-learn --spam --progress /var/spool/cyrus/mail/domain/w/wormnet.eu/r/admin/rejected/spamassassin/*.
+  sa-learn --spam --progress /var/spool/cyrus/mail/domain/w/wormnet.eu/m/user/mb/spam/*.
 ===== DKIM =====
@@ Line 71: / Line 104: @@
   INSERT INTO dkim VALUES ('wormnet.eu', 'cat');
-Then generate a keypair on marmot:
+Then generate a keypair on marmot (1024-bit considered right in 2014; latterly 2048 suggested in RFC8301):
+  SELECTOR="cat"
   cd /etc/exim4/dkim
   mkdir -m 750 wormnet.eu
   cd wormnet.eu
-  openssl genrsa -out cat 1024
+  openssl genrsa -out ${SELECTOR} 1024
-  openssl rsa -in cat -out cat.pub -pubout -outform PEM
+  openssl rsa -in ${SELECTOR} -out ${SELECTOR}.pub -pubout -outform PEM
-  chmod o= cat*
+  chmod o= ${SELECTOR}*
+  echo "v=DKIM1; h=sha256; p=$(grep -vE '^\-\-\-' ${SELECTOR}.pub | tr -d '\n'); t=s;"
 And finally mangle the public key into a DNS TXT record. See [[http://www.zytrax.com/books/dns/ch9/dkim.html|here]] for some tweakables.
-  _adsp._domainkey IN TXT "dkim;"
+  _adsp._domainkey IN TXT "dkim=all;"
-  cat._domainkey   IN TXT "v=DKIM1; h=sha256; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCzl70kXqRENAgRfWRZ2WyvLtdQe22E1OvZMgIAwPV8GHraN2z0YCXgkeO7DW5t/0sOOa9z/hOmASTilds0oo2qgCmcJwV/YzGNAY0nw1CWAawIr5LlkLGzrLwvSv69iMsQJlsHMbqij0ljQpVuJ+DY5S0FYsgMlnyYWgE4EmEL5wIDAQAB; t=s"
+  cat._domainkey   IN TXT "v=DKIM1; h=sha256; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCzl70kXqRENAgRfWRZ2WyvLtdQe22E1OvZMgIAwPV8GHraN2z0YCXgkeO7DW5t/0sOOa9z/hOmASTilds0oo2qgCmcJwV/YzGNAY0nw1CWAawIr5LlkLGzrLwvSv69iMsQJlsHMbqij0ljQpVuJ+DY5S0FYsgMlnyYWgE4EmEL5wIDAQAB; t=s;"
+==== key rotation ====
+Just make a new keypair (with a new name) / and associated TXT record. Then ''UPDATE'' your row in the ''dkim'' table. The old TXT record can be deleted after a week.
+People seem to think rotating keys quarterly is a good idea.
 ===== Allowing mail relaying from particular hosts =====
@@ Line 92: / Line 132: @@
 Mail on wormnet is provided by the following Debian packages (where a * denotes a backport from testing or unstable or experimental):
-  * exim4-daemon-heavy* (MTA) //(need to hack the ''debian/control'' file to change build dependency from ''libdb5.1-dev'' to ''libdb4.8-dev'')//
+  * exim4-daemon-heavy* (MTA) //(need to hack the ''debian/control'' file to change build dependency from ''libdb5.1-dev'' to ''libdb4.8-dev'', and the ''debian/rules'' file to uncomment ''OPENSSL:=1'')//
     * clamav-daemon (antivirus)
     * spamassassin (main anti-spam thing, plus lots of friggery)