fix(smtp-server): encode subject to UTF-8 before database insertion#3594
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DamienLGRCA wants to merge 1 commit into
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fix(smtp-server): encode subject to UTF-8 before database insertion#3594DamienLGRCA wants to merge 1 commit into
DamienLGRCA wants to merge 1 commit into
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Emails with subjects containing non-UTF-8 characters (e.g. ISO-8859-1 encoded accented characters like 'é' as raw \xE9) cause a Mysql2::Error 'Incorrect string value' when Postal attempts to insert the message into the database. This results in the email being silently dropped. This commit adds an encode_utf8 helper that: 1. Returns the string as-is if already valid UTF-8 2. Attempts to re-interpret bytes as UTF-8 3. Falls back to ISO-8859-1 to UTF-8 conversion (most common case for European accented characters) 4. As a last resort, replaces invalid characters with '?' This fixes the issue reported in postalserver#1636 where emails sent with ISO-8859-1 encoded subjects without RFC 2047 MIME encoding are rejected by MySQL.
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Problem
Emails with subjects containing raw non-UTF-8 characters (e.g. ISO-8859-1
\xE9for "é") without RFC 2047 MIME encoding causeMysql2::Error: Incorrect string valueduring insertion into the messages table. The email is silently dropped — never delivered to the endpoint.This is an issue that has existed since at least 2021 (see #1636). In environments receiving mail from legacy systems (ERPs, invoicing software), this can affect hundreds of emails per day.
Root cause
In
lib/postal/message_db/message.rb, the subject is extracted viaheaders["subject"]&.last.to_s[0, 200]and inserted as-is. TheMailgem'sfield.decodedcorrectly handles RFC 2047 encoded headers (=?ISO-8859-1?Q?...?=), but when the sender does not encode the subject per RFC 2047 (raw ISO-8859-1 bytes), the string is passed through unchanged. MySQL in strict mode then rejects the invalid UTF-8.Fix
Added a private
encode_utf8method that safely converts the subject to valid UTF-8:?Reproduction
Results in:
Closes #1636