Search found 31 matches

by AITCS
10 May 2018 22:56
Forum: 3.x How-to
Topic: Customise postfix reject messages
Replies: 0
Views: 370

Customise postfix reject messages

Hi all, Just wondering if there's a simple way to customise postfix reject messages when a file type restriction is encountered? e.g. we block all zip/exe/com files, and currently senders will receive a "5.7.1 message content rejected" bounce if they attempt to send a file in the reject list to one ...
by AITCS
06 May 2018 01:15
Forum: 3.x How-to
Topic: Use Postfix to block sender with certain text
Replies: 7
Views: 503

Re: Use Postfix to block sender with certain text

Okay, I realise where the problem is occurring... The spammy from address is only sent during the "mail from:" part of the SMTP conversation, which is not tested by header_checks. I did manage to resolve the issue, and will post here for future reference. Let's make a new sender restriction based on...
by AITCS
06 May 2018 00:01
Forum: 3.x How-to
Topic: Use Postfix to block sender with certain text
Replies: 7
Views: 503

Re: Use Postfix to block sender with certain text

Deleted post. Useless content.
by AITCS
05 May 2018 08:46
Forum: 3.x How-to
Topic: Use Postfix to block sender with certain text
Replies: 7
Views: 503

Re: Use Postfix to block sender with certain text

Curiousity got the better of me... Unfortunately no luck with your solution. It still lets the emails straight through to MailScanner. Do we need to postmap the header_checks file for it to work or not? There is a header_checks.db file in /etc/postfix. I have renamed it temporarily as I think we've ...
by AITCS
05 May 2018 07:44
Forum: 3.x How-to
Topic: Use Postfix to block sender with certain text
Replies: 7
Views: 503

Re: Use Postfix to block sender with certain text

Very detailed answer, thank you very much for your efforts.
I'll give it a try in the morning as it's approaching close of business on this side of the world.
Will report back after we've implemented and tested.
by AITCS
05 May 2018 01:46
Forum: 3.x How-to
Topic: Use Postfix to block sender with certain text
Replies: 7
Views: 503

Use Postfix to block sender with certain text

Hi all, I have an interesting issue... someone out there really enjoys sending mail to our server from numerous compromised servers, IPs are all over the place, but they are targeting one specific user in our system. The only common thing I can find in all of the mail is that there is a certain stri...
by AITCS
07 Mar 2018 11:42
Forum: 3.x Bugs
Topic: Whitelisted address not consistently working
Replies: 14
Views: 1297

Re: Whitelisted address not consistently working

You are a champion... I've made the change. Now to sit back and wait for the next bulk mailing.
I've asked the user to notify me when it's about to occur, so I'll watch the MailWatch log to ensure that it treats it properly.
I'll report back once verified. Thanks once again!
by AITCS
07 Mar 2018 09:39
Forum: 3.x Bugs
Topic: Whitelisted address not consistently working
Replies: 14
Views: 1297

Re: Whitelisted address not consistently working

It's been in the white list since before I discovered this "issue". Some emails from that user are being whitelisted and pass straight through, but for some very odd reason when it's a bulk email, it gets scanned and whitelisting seems to be ignored. Single emails pass through green just like your t...
by AITCS
07 Mar 2018 08:01
Forum: 3.x Bugs
Topic: Whitelisted address not consistently working
Replies: 14
Views: 1297

Re: Whitelisted address not consistently working

Just perusing the logs and it looks like they've just sent a couple of email blasts. What has worked: SpamAssassin rule which applies a -10.0 value to email with their address in the FROM header. What didn't work: trusted_networks in local.cf. MailWatch still shows it as a 'scanned' email and not wh...
by AITCS
07 Mar 2018 05:31
Forum: 3.x Bugs
Topic: Whitelisted address not consistently working
Replies: 14
Views: 1297

Re: Whitelisted address not consistently working

Absolutely will do... I often refer back to the forum for things I've said and since forgotten. Always helpful to get a record of it.
by AITCS
06 Mar 2018 22:02
Forum: 3.x Bugs
Topic: Whitelisted address not consistently working
Replies: 14
Views: 1297

Re: Whitelisted address not consistently working

I have added the Exchange server IP to the trusted network. Just need to wait for the next bulk run to see if it works or not.
It only happens once a week or thereabouts, so might need to wait a few more days. Cheers.
by AITCS
06 Mar 2018 10:57
Forum: 3.x Bugs
Topic: Whitelisted address not consistently working
Replies: 14
Views: 1297

Re: Whitelisted address not consistently working

Yeah, one of the bigger rules was no one listed in the TO field (since they BCC everyone for privacy).
I might suggest that they address the email to themselves to save a couple of spam points.
by AITCS
05 Mar 2018 22:04
Forum: 3.x Bugs
Topic: Whitelisted address not consistently working
Replies: 14
Views: 1297

Re: Whitelisted address not consistently working

Thanks for the pointers. I'll give the trusted network a try and see what happens. It's hard to describe to the client how to make the emails less spammy, which is why I thought whitelisting the email address they use should have worked. It does work fine when they send to a low number of recipients...
by AITCS
05 Mar 2018 12:00
Forum: 3.x Bugs
Topic: Whitelisted address not consistently working
Replies: 14
Views: 1297

Whitelisted address not consistently working

Since "whitelist" isn't a searchable term on here I'm having to make this query (sorry). I have recently added a new client to our email hosting. We use Exchange 2013, and EFA sits in between the real world and the Exchange server filtering in both directions. We've had pretty much zero problems for...
by AITCS
17 Feb 2018 02:01
Forum: 3.x How-to
Topic: Block by from email domain
Replies: 6
Views: 818

Re: Block by from email domain

rickriv90210 wrote:
16 Feb 2018 16:32
How can I request a new feature for the ability to block by from email domain?
I've just run into the situation where I'd like to implement this feature also (via sender_access, not blacklists).
I have a feeling I once configured something similar in the past, but having a mental block right now.
by AITCS
06 Dec 2017 22:40
Forum: Discussion
Topic: Double extensions - Still blocked after disabling
Replies: 1
Views: 211

Re: Double extensions - Still blocked after disabling

Figured out what it was... one of the extensions was being picked up in mime_header_checks so Postfix was binning the file before MailScanner even got to see it.

I'll leave this here as a reminder.
by AITCS
06 Dec 2017 21:53
Forum: Discussion
Topic: Double extensions - Still blocked after disabling
Replies: 1
Views: 211

Double extensions - Still blocked after disabling

Hi all, I've followed the instructions on this forum to allow double extension file names, but I'm still seeing 5.7.1 message content rejected coming up in our logs. What would be the best procedure to test why this still might be occurring? We have a client who needs to drop this rule due to them r...
by AITCS
06 Nov 2017 11:07
Forum: 3.x How-to
Topic: Allow external SMTP auth for relay
Replies: 12
Views: 2233

Re: Allow external SMTP auth for relay

Happy to help.
Hopefully it proves helpful to others also.
by AITCS
06 Nov 2017 06:08
Forum: 3.x How-to
Topic: Allow external SMTP auth for relay
Replies: 12
Views: 2233

Re: Allow external SMTP auth for relay

Lucky for you I scribbled down notes as I did this. Hopefully they make sense. Create a new user account for the external user before starting. These details will be used toward the end of the procedure. Also, don't forget to open port 587 to EFA. nano /etc/postfix/master.cf remove # from line #subm...
by AITCS
30 Aug 2017 07:32
Forum: 3.x How-to
Topic: Allow external SMTP auth for relay
Replies: 12
Views: 2233

Re: Allow external SMTP auth for relay

We don't want to expose Exchange any more than port 443 for our Outlook users.
Having EFA sitting in between provides a good layer of protection between the outside world and Exchange.
by AITCS
29 Aug 2017 04:57
Forum: 3.x How-to
Topic: Allow external SMTP auth for relay
Replies: 12
Views: 2233

Re: Allow external SMTP auth for relay

Got it working... had to use a combination of the posts to get it working, but the contractor can now send using our EFA server as an SMTP server after authentication via TLS on port 587. Thanks for the links above, and looking forward to any future developments being able to do this natively as hin...
by AITCS
27 Aug 2017 01:13
Forum: 3.x How-to
Topic: Allow external SMTP auth for relay
Replies: 12
Views: 2233

Re: Allow external SMTP auth for relay

Many thanks Shawn... we'll test on Monday when back in the office.
by AITCS
25 Aug 2017 01:07
Forum: 3.x How-to
Topic: Allow external SMTP auth for relay
Replies: 12
Views: 2233

Allow external SMTP auth for relay

Pardon my ignorance, but our knowledge only extends far enough to get EFA installed and working perfectly, but not for modifying the configuration very much. We'd like to achieve the following if possible, and would appreciate any insight as to how we can make it happen. We would like to allow an ex...
by AITCS
18 Apr 2017 07:54
Forum: 3.x Bugs
Topic: Upgrade from 3.0.1.9 to 3.0.2.1
Replies: 3
Views: 1012

Re: Upgrade from 3.0.1.9 to 3.0.2.1

I noticed this happen in far more versions that just the latest.
Never worried about it as freshclam always worked fine, even via cron.
Happy to see a resolution for it though.
by AITCS
30 Mar 2017 02:05
Forum: 3.x Bugs
Topic: Error: unable to validate security token
Replies: 2
Views: 1271

Re: Error: unable to validate security token

Flush web cache and cookies apparently resolves this.
Didn't permanently work in my case, but easy enough to try.