[1] [CITE[qmail RFC violations]] ([TIME[2005-12-14 00:00:05 +09:00]] 版) <http://ya.maya.st/mail/qmail-violations.html#8bitmime>

[2] [CITE@en[RFC 6152 - SMTP Service Extension for 8-bit MIME Transport]]
([TIME[2015-11-29 17:47:51 +09:00]] 版)
<https://tools.ietf.org/html/rfc6152>

[3] [CITE@en[RFC 1652 - SMTP Service Extension for 8bit-MIMEtransport]]
([TIME[2015-11-15 20:58:46 +09:00]] 版)
<https://tools.ietf.org/html/rfc1652>