As it seems in rfc2821:
The maximum total length of a text line including the <CRLF> is
1000 characters (not counting the leading dot duplicated for
transparency). This number may be increased by the use of SMTP
Service Extensions.
If I am not wrong (I really may be here), the subject header should be
on one line, so the size should be approximately 1000 characters.
Odhiambo Washington wrote:
> Hello everyone,
>
> Today, a customer reported to me having received an e-mail which had
> everything (I mean what would under normal circumstances go into the
> body) as part of the subject.
>
> This kind of spam can be blocked, but I am wondering:
>
> (a) What is, according to the RFCs, supposed to be the acceptable
> maximum length for the subject line?
> (b) Which acl_smtp_* would be the best to block this type of spam?
> (c) Finally, can someone vote their rule as the best/most effective
> against such spam? I need to copycat that one which is considered
> the best ;)
>
>
