email addresses with special characters
in [Sendmail]
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From: mtwill on 7 Apr 2010 20:05 I have noticed lately that a spammer has been sending messages to my mail server that start with the pipe ( | ) special character. This cause sendmail to bounce back a reply with a 550 error " Cannot mail directly to programs". Is there a way that I can reject the message if the email address that it is sent to begins with a pipe ( | ). Thanks Myron
From: mikea on 8 Apr 2010 09:57 mtwill <myron(a)wcstc.com> wrote in <91ead55b-892a-46aa-8fc1-5d61e53ac06d(a)k13g2000yqe.googlegroups.com>: > I have noticed lately that a spammer has been sending messages to my > mail server that start with the pipe ( | ) special character. This > cause sendmail to bounce back a reply with a 550 error " Cannot mail > directly to programs". > Is there a way that I can reject the message if the email address > that it is sent to begins with a pipe ( | ). Install and configure a milter that can check for the text that you find objectionable. I use milter-regex for such things, and it works nicely for me. -- Mike Andrews, W5EGO mikea(a)mikea.ath.cx Tired old sysadmin
From: Robert Bonomi on 8 Apr 2010 16:32 In article <91ead55b-892a-46aa-8fc1-5d61e53ac06d(a)k13g2000yqe.googlegroups.com>, mtwill <myron(a)wcstc.com> wrote: >I have noticed lately that a spammer has been sending messages to my >mail server that start with the pipe ( | ) special character. This >cause sendmail to bounce back a reply with a 550 error " Cannot mail >directly to programs". That's not just a 'spammer', that is an attempt to _break_into_ your system, probably for the purposes of making it part of a 'botnet'. >Is there a way that I can reject the message if the email address >that it is sent to begins with a pipe ( | ). What do you want to do _beyond_ what is already being done? Sendmail *already* rejects mail to any such address, with the error indication shown.
From: mtwill on 8 Apr 2010 18:06 On Apr 8, 2:32 pm, bon...(a)host122.r-bonomi.com (Robert Bonomi) wrote: > In article <91ead55b-892a-46aa-8fc1-5d61e53ac...(a)k13g2000yqe.googlegroups..com>, > > mtwill <my...(a)wcstc.com> wrote: > >I have noticed lately that a spammer has been sending messages to my > >mail server that start with the pipe ( | ) special character. This > >cause sendmail to bounce back a reply with a 550 error " Cannot mail > >directly to programs". > > That's not just a 'spammer', that is an attempt to _break_into_ your > system, probably for the purposes of making it part of a 'botnet'. > > >Is there a way that I can reject the message if the email address > >that it is sent to begins with a pipe ( | ). > > What do you want to do _beyond_ what is already being done? Sendmail > *already* rejects mail to any such address, with the error indication > shown. When sendmail rejects a message is generates a bounce message which causes back scatter. I would like to just reject the message before I receive it. This way it will not generate the bounce message.
From: D. Stussy on 8 Apr 2010 19:56
"mtwill" <myron(a)wcstc.com> wrote in message news:76748f37-8965-49d2-9c93-55dc87037e60(a)w42g2000yqm.googlegroups.com... On Apr 8, 2:32 pm, bon...(a)host122.r-bonomi.com (Robert Bonomi) wrote: > In article <91ead55b-892a-46aa-8fc1-5d61e53ac...(a)k13g2000yqe.googlegroups.com>, > > mtwill <my...(a)wcstc.com> wrote: > >I have noticed lately that a spammer has been sending messages to my > >mail server that start with the pipe ( | ) special character. This > >cause sendmail to bounce back a reply with a 550 error " Cannot mail > >directly to programs". > > That's not just a 'spammer', that is an attempt to _break_into_ your > system, probably for the purposes of making it part of a 'botnet'. > > >Is there a way that I can reject the message if the email address > >that it is sent to begins with a pipe ( | ). > > What do you want to do _beyond_ what is already being done? Sendmail > *already* rejects mail to any such address, with the error indication > shown. When sendmail rejects a message is generates a bounce message which causes back scatter. I would like to just reject the message before I receive it. This way it will not generate the bounce message. ----- By default, sendmail issues a reject message, not a bounce NDR. If you're generating bounces, then you have broken your configuration. Scrap it and start over, because you're doing something wrong. |