Hello Konstantin,

Please look at 
https://www.exim.org/exim-html-current/doc/html/spec_html/ch-access_control_lists.html
 and look at the description after “
delay = <time>
“

Jan

(Sorry for top posting, editing sucks on cell)

> 9. sep. 2019 kl. 16:37 skrev Konstantin Boyandin via Exim-users 
> <exim-users@exim.org>:
> 
> Hello Jan,
> 
> "delay" means tarpitting, in this context?
> 
> I wonder how efficient that is.
> 
> Sincerely,
> Konstantin
> 
>> On 09.09.2019 21:16, Jan Ingvoldstad via Exim-users wrote:
>> I've had another variant for years:
>> 
>> acl_check_mail:
>>  deny
>>    message = no HELO given before MAIL command
>>    condition = ${if def:sender_helo_name {no}{yes}}
>>    delay = 60s
>> 
>> The delay is a nice touch, if you have the TCP connections to spare.
>> 
>> Jan
>> 
>> On Mon, Sep 9, 2019 at 4:10 PM Phillip Carroll via Exim-users <
>> exim-users@exim.org> wrote:
>> 
>>> my configuration has had something similar for years. Is there any
>>> significant difference?
>>> 
>>> acl_check_mail:
>>>   # deny any mail without helo name
>>>   deny    message = HELO required before MAIL
>>>           condition = ${if eq{$sender_helo_name}{} {1}}
>>> 
>>> (Yours obviously simpler to read)
>>> 
>>>> On 9/6/2019 6:16 PM, Phil Pennock via Exim-users wrote:
>>>>> On 2019-09-06 at 22:04 +0200, Heiko Schlittermann via Exim-users wrote:
>>>>> The HELO ACL doesn't help either, as the first EHLO comes before
>>>>> STARTTLS, and the second EHLO doesn't have to come, the client may send
>>>> 
>>>> Oh pox.  My memory is going.  I hadn't realized that my protection
>>>> against this comes from long-standing local configuration, not Exim
>>>> defaulting to enforcing this:
>>>> 
>>>> acl_check_mail:
>>>>   deny    message       = 503 Bad sequence of commands - must send
>>> HELO/EHLO first
>>>>           condition     = ${if !def:sender_helo_name}
>>>> 
>>>> If anyone wants to protect against stupidity: I've been using that guard
>>>> for "longer than the five years that the current mail-server is running"
>>>> and I'm not going diving through git history to find when it was
>>>> introduced to my older server.
>>>> 
>>>> To the best of my knowledge, that has never blocked legitimate mail.
>>>> Everyone does EHLO after STARTTLS.
>>>> 
>>>> Exim drops pre-TLS sender_helo_name after negotiating TLS.  This is
>>>> required by RFC 3207 (section 4.2) but not explicitly mentioned in the
>>>> Exim Spec, AFAICT.
>>>> 
>>>> -Phil
> 
> 
> 
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