diff --git a/jiramail/change.py b/jiramail/change.py
index fca9931..d661410 100644
--- a/jiramail/change.py
+++ b/jiramail/change.py
@@ -73,6 +73,8 @@ def command_issue_comment(issue: jira.resources.Issue,
     try:
         if not dry_run:
             jiramail.jserv.jira.add_comment(issue, text)
+        else:
+            logger.critical("add comment to %s: %s", issue.key, text.encode())
 
     except jira.exceptions.JIRAError as e:
         return jiramail.Error(f"unable to add comment to issue {issue.key}: {e}")
@@ -522,6 +524,31 @@ def process_mail(mail: email.message.Message,
     return rc
 
 
+def comment_mail(mail: email.message.Message) -> bool:
+    key = find_issue_key(mail)
+    if not key:
+        logger.critical("issue number not found. Maybe it's because you don't reply to the generated email.")
+        return False
+
+    try:
+        issue = jiramail.jserv.jira.issue(key)
+    except jira.exceptions.JIRAError as e:
+        logger.critical("unable to get %s issue: %s", key, e.text)
+        return False
+
+    for part in mail.walk():
+        if part.get_content_type() != "text/plain":
+            continue
+
+        res = command_issue_comment(issue, part.get_payload())
+
+        if isinstance(res, jiramail.Error):
+            logger.critical("%s", res.message)
+            return False
+
+    return True
+
+
 def main(cmdargs: argparse.Namespace) -> int:
     global dry_run, no_reply
 
diff --git a/jiramail/smtp.py b/jiramail/smtp.py
index 459bcfd..2d70f3c 100644
--- a/jiramail/smtp.py
+++ b/jiramail/smtp.py
@@ -7,6 +7,7 @@
 import argparse
 import email
 import email.message
+import email.utils
 import re
 import socket
 
@@ -170,6 +171,14 @@ def command_rcpt(state: Dict[str, Any], args: str) -> SMTPAnswer:
     return SMTPAnswer("250 2.1.5 Ok\r\n")
 
 
+def get_mode(mail: email.message.Message) -> str:
+    for e in mail.get_all("To", []):
+        (_, addr) = email.utils.parseaddr(e)
+        if addr == "comment@jira":
+            return "comment"
+    return "change"
+
+
 def command_data(state: Dict[str, Any]) -> SMTPAnswer:
     if "user" in state and not state["authorized"]:
         return SMTPAnswer("530 Authentication required\r\n")
@@ -203,9 +212,15 @@ def command_data(state: Dict[str, Any]) -> SMTPAnswer:
 
     replies: List[email.message.EmailMessage] = []
 
-    if not jiramail.change.process_mail(mail, replies):
-        logger.critical("error: mail processing failed")
-        return SMTPAnswer("451 4.3.0 Requested action aborted: local error in processing\r\n")
+    match get_mode(mail):
+        case "comment":
+            if not jiramail.change.comment_mail(mail):
+                logger.critical("error: mail processing failed")
+                return SMTPAnswer("451 4.3.0 Requested action aborted: local error in processing\r\n")
+        case _:
+            if not jiramail.change.process_mail(mail, replies):
+                logger.critical("error: mail processing failed")
+                return SMTPAnswer("451 4.3.0 Requested action aborted: local error in processing\r\n")
 
     if "mbox" in state:
         for reply in replies: