>返信先指定のIn-Reply-To と
>Referencesが、essaipc=えっさいPC 宛になってるが?(爆笑
4.6.2. IN-REPLY-TO
The contents of this field identify previous correspon-
dence which this message answers. Note that if message iden-
tifiers are used in this field, they must use the msg-id
specification format.
4.6.3. REFERENCES
The contents of this field identify other correspondence
which this message references. Note that if message identif-
iers are used, they must use the msg-id specification format.