Why is it a bad idea to use customer email as from address
I’ve got an application that emails users once they have filled in a form. It uses a no-reply@customerdomain.com as a from address. The customer wants it to use the email from the form as the from address which could be anything. I have been told that this is a bad idea due to spoofing/blacklisting and spam. I feel really vague about the exact reason about why this is a bad idea particularly as i’ve got [...]
Continue Reading »IMAP standard folder names – “Junk” or “Spam”
I am configuring spamassassin at the moment and have been wondering what is the standard (or atleast most used and recognized by most clients) folder name for Spam or Junk? I first used Spam, but then notized that my preferred webmailer, roundcube, uses Junk by default. This can of course be changed, but I am wondering which is the name used by the majority of clients. The other names I use are: INBOX, Sent, Trash, [...]
Continue Reading »Spam received to mystery “users” email group
This morning, our entire company received a spam message sent to users@ourdomain.on.ca, where ourdomain.on.ca is our actual domain. There is a distinguished name that this could correspond to: CN=Users,DC=ourdomain,DC=on,DC=ca Looking at the attributes though, there is no mail, no proxyAddresses, no signs that there is a mailbox configured there. I did some LDAP queries, searching for: (proxyAddresses=smtp:users@ourdomain.on.ca) (mail=users@ourdomain.on.ca) But am not seeing any records. (I also search for known email addresses to ensure the tree [...]
Continue Reading »Spam or exchange issue?
I am getting an error message to unknow user on my domain. I would like to know is this just a phishing spam email or it was really send from our domain? I have changed our domain name to OURDOMAIN.COM I have Exchange 2010 installed. Body of the email is Delivery has failed to these recipients or distribution lists:sales The recipient’s e-mail address was not found in the recipient’s e-mail system. Microsoft Exchange will not [...]
Continue Reading »removing spam between mail server and client
My postfix was badly configured and let a lot of spam emails through to an account. I’ve fixed postfix now so it’s become a much better spam filter, and almost no new spam is getting through. However, there are still a lot of old spam emails on the server which I would like to remove somehow. These are Maildir style email files (ie one file per email). Is there a command line tool for going [...]
Continue Reading »Bulk email prevent blocking
We are going to send huge bulk emails (It’s an invitation to our site). I setup an instance on Amazon and installed zimbra on that along with phplist which is configured. DKIM and Domain keys are setup. I am afraid my IP will be blocked by spam blockers so is there any way that I can tell them my IP address and they do not block my ip. Our emails are not spam but it [...]
Continue Reading »Configuring postfix to fight spam, 2012 edition
I’m running a small (20 users, 30 mailman-lists) server with postfix. I think it’s configured fine, more or less. I spent 2 days reading up on all kinds of material on postfix configuration, but I couldn’t find any list of measures that are actually safe to enable/disable. For about every configuration option i found there were some people pro and some against it. This is my postfix configuration, can you give me simple measures on [...]
Continue Reading »Track spammer Exim
hello i have a exim server , and have a lot of spam last 24 hours , i watch exim_mainlog and see this 1SDcCZ-0005DX-JQ-H mailnull 47 12 <contact@xxxxxxxx.com> 1333115355 0 -helo_name eicghqfebwyn -host_address 186.106.221.159.3741 -host_name 186-106-221-159.fastnet.com -host_auth courier_login -interface_address 190.38.1.34 -received_protocol smtp -body_linecount 3 -max_received_linelength 228 -auth_id contact@xxxxxxxx.com -deliver_firsttime XX 10 mcats21@gmail.com bently.fistwird@hotmail.com gunna10@yahoo.com f-d.9@hotmail.com anandajit26@yahoo.com kolkata.enjoy@gmail.com ajtoney14@yahoo.com ben.storm@t-online.de superman25_2005@yahoo.com stagedawg@gmail.com227P Received: from 186-106-221-159.fastnet.com([186.106.221.159] helo=eicghqfebwyn) by srv.xxx.net with smtp (Exim 4.69) (envelope-from <contact@xxxxxxxx.com>) id 1SDcCZ-0005DX-JQ; [...]
Continue Reading »Does the server hostname need to match the domain name of the email address you are sending from? Does the hostname need to be verifiable with DNS?
I am trying to diagnose why email won’t send from a new RHEL v5.8 server. Sendmail is up and running, but everything is stuck in the queue (confirmed with mailq) with connection timed out errors. If I have the hostname of the server to: natulwebserver01.bto.com But try to send emails with PHP and set the ‘from’ email address to: no-reply@dataportal.com …this would cause the destination mail servers to block the emails right? If so, does [...]
Continue Reading »Clean out a large MediaWiki text table
I just discovered that an old MediaWiki of mine was infested with spam, and the database table named “text” (which contains the page content) is 3GB large. I’ve deleted all the spam pages manually, but: The table is still the same size. I wonder how it got to 3GB anyway. There wasn’t that much spam (about a hundred medium-sized pages) How can I get rid of this mess? If you want to inspect the wiki, [...]
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