diff --git a/.github/actions/spelling/allow.txt b/.github/actions/spelling/allow.txt
index f27a86f9a..446b94080 100644
--- a/.github/actions/spelling/allow.txt
+++ b/.github/actions/spelling/allow.txt
@@ -1,4 +1,5 @@
 aarch
+APPENDLIMIT
 bitmask
 bitmasks
 configurations
diff --git a/data/settings.js b/data/settings.js
index dc91e6c25..940aca38a 100644
--- a/data/settings.js
+++ b/data/settings.js
@@ -3262,7 +3262,8 @@ used. Used only with [[link,quota_driver_imapc]].`
 		seealso: [ '[[link,quota_mail_size]]' ],
 		text: `
 The maximum message size that is allowed to be saved (e.g. by LMTP, IMAP
-APPEND or [[doveadm,save]]).`
+APPEND or [[doveadm,save]]). If configured, will also be advertized with
+\`APPENDLIMIT\` extensions for IMAP clients, and \`SIZE\` extension for LMTP clients.`
 	},
 
 	quota_mailbox_count: {
diff --git a/docs/core/summaries/rfc.md b/docs/core/summaries/rfc.md
index cf04d5f1e..ae0ed6ad3 100644
--- a/docs/core/summaries/rfc.md
+++ b/docs/core/summaries/rfc.md
@@ -99,6 +99,7 @@ This is a non-exhaustive list of RFCs that Dovecot implements/supports.
   Quick Mailbox Resynchronization (QRESYNC) (updated RFC 4551 and RFC 5162)
   ([[rfc,7162]])
 - IMAP4 Non-synchronizing Literals (updated RFC 2088) ([[rfc,7888]])
+- IMAP4 APPENDLIMIT Extension ([[rfc,7889]])
 - IMAP Extension for STATUS=SIZE ([[rfc,8438]])
 - IMAP4 Extension for Returning MYRIGHTS Information in Extended LIST ([[rfc,8440]])
 - IMAP “$Important” Keyword and “\\Important” Special-Use Attribute