This guide assumes you have a working Postfix server and want it to sign with DKIM. There are a few things we have to understand to make all of this work though, which require you to be familiar with DNS as well. 1.) Install OpenDKIM apt install opendkim systemctl enable opendkim 2.) Edit /etc/opendkim.conf Syslog yes SyslogSuccess yes Mode&nbs........

This will be the goto to help solve e-mail delivery issues and talk about many practical issues that happen between developers, admins and scripts that send e-mail and do things that may not be acceptable or cause deliverability problems. Sendmail Stuff Edit /etc/mail/sendmail.mc The problem is that if you send directly out from the server using the mail function, the Return-path of the e-mails will be username@thehostnameoftheserver.com. Let........

Aug 10 01:11:54 mailserver postfix/smtp[6180]: 020AE17C2BD1: to=, relay=none, delay=0.29, delays=0.28/0/0/0, dsn=5.4.4, status=bounced (Host or domain name not found. Name service error for name=gmail.con type=A: Host not found) A user complained that their e-mails weren't being delivered but they actually made a small typo and used gmail.con so it wasn't working as expected of course........

Jul 3 22:12:17mailserver postfix/smtpd[6195]: fatal: no SASL authentication mechanisms Jul 3 22:12:18mailserver postfix/master[4881]: warning: process /usr/libexec/postfix/smtpd pid 6195 exit status 1 Jul 3 22:12:18mailserver postfix/master[4881]: warning: /usr/libexec/postfix/smtpd: bad command startup -- throttling This only ever happens in my experience when the authentication method is actually Dovecot. Usually the problem........

This happens because Dovecot limits the maximum IMAPconnections per IPto just 10. This may be fine for a single client side IPbut if an entire office or multiple users are behind one IPor a single heavy user is active then you will get bizarre errors in your e-mail clients such as "Password Incorrect" or similar in Thunderbird. It won't be obvious on the client side as to what the problem is and they will probably just think the server is misconfi........

In Thunderbird in a very large folder suddenly all of my e-mail list became blank/white even though you could click on the invisible/white/blank lines and it would show the e-mails. Itried to close and reopen but only going to Folder -> Properties and clicking Repair Folder fixed it (basically it had to redownload/rebuild the entire index and all e-mails).........

This actually only happened after an e-mail server ran out of space due to run away log files. Normal Desktop clients were not affected. It appeared to be a bug in K9 mail but even reinstalling/wiping all settings did not fix it (read e-mails would still not reappear). This is moreso a bug in Dovecot where it probably messes up the index files. How do you fix this in Dovecot/your e-mail server? You need to delete the do........

The most common solution is to use the /etc/postfix/header_checks but this is a big problem. Why is header_checks a problem? Because it does it to all mail whether incoming or outgoing and whether authenticated or not. We of course want as much header information for incoming as we can get for many reasons but many organizations want to secure and make their mail clients as secure as possible. I adapted this solution to the client's custom config, they are configur........

It's just a simple plugin that you get from here. After that you can stopped having a barrage of annoying e-mails from WP:)........

This error seems to happen randomly and especially when trying to send e-mails. Apparently it's a long-standing GNome bug but is also partially the default of Thunderbird depending on who you ask. There is no known fix that I'm aware of except to upgrade gnome and the gvfs package but this is not an option for older versions/distributions. An error occurred while loading or saving configuration information for thunderbird. Some of your configuration settings may not........

CPanel says you can access 98% of the functions through CLI which experienced Unix/Linux admins prefer for simplicity and for scripting.  I've never found CPanel easy to use from the admin panel, it seems everything is hard to find and a simple task becomes a series of hunts. So for people like me here's the list: http://cpanel.net/system-administrators/command-line-scrip........

After the "latest" update one of our clients asked us to figure out the issue and it turns out it is related to the mail settings. Basically all e-mails were being sent with blank text/no body. The solution Go to "Setup ->General Settings ->Mail" and just click on "Save" and it will work again. Note that this assumes you didn't break things yourself by changing any settings. WHMCS may tell y........

*Note this will delete all comments indiscriminately. DELETE FROM `wp_comments` To delete all but save specific comments based on "author e-mail use the following". Add more e-mails below in the same format if you have more. DELETE FROM `wp_comments` WHERE NOT comment_author_email IN ('user@hotmail.com','another@hotmail.com')........

relay=alt4.gmail-smtp-in.l.google.com. [74.125.136.26], dsn=4.0.0, stat=Deferred: 421-4.7.0 [ 10] Our system has detected an unusual rate of This is strange because the mail server IP is not blacklisted anywhere and the IP itself has not been used for years and this server is clean and has only sent a few e-mails to gmail.com in its entire time. I wonder if this is a legacy block on a whole range of IPs as punishment for others in the block........

Jul 11 15:20:58 tor sendmail[9617]: r6AKjOD07: to= mailserver.com was the hostname of the server, sendmail sends this by default and many mailservers will reject mail to a hostname that does not resolve or exist. The easiest way is just to change the hostname and make sure it does resolve to something. I read there is a way in sendmail.mc to manually set a hostname but I never got it working: vi /etc/mail/sendmail.mc define(`confDOMAIN........

On occassion and from a variety of networks and clients, Sent messages don't get saved. I'm wondering if these log messages could be why: May 3 14:16:39 mail.box postfix/smtpd[5195]: connect from 192.168.1.58 May 3 14:16:39 mail.box postfix/smtpd[5195]: SSL_accept error from 192.168.1.58: -1 May 3 14:16:39 mail.box postfix/smtpd[5195]: lost connection after CONNECT from 192.168.1.58 May 3 14:16:39 mail.box postfix/smtpd[5195]:........

Here's a proven example of what a bad hard drive can do, it was technically functioning OKin a RAID array but the system became extremely low and the load become high and IOWAIT was even higher and I always thought it was a bad application. The truth is that this failing 1TBHitachi has slowly gotten worse and caused huge slowdowns, (eg. 100% load on Thunderbird waiting for e-mails to load etc..). After swapping it out, tabs change instantly, emails are not lagged, and........

Step #1 - Create Wrapper Script vi /usr/local/bin/phpsendmail #!/usr/bin/php ........

I experienced this with CPanel's Exim after an auto-update (a Google of this error produces lots of complaints with few clear solutions). In this case I'll put the solution at the top. Run /scripts/buildeximconf to rebuild the Exim config and it should be fine after that. mail -vs "from test" user@dest.com < .bash_history LOG: MAIN cwd=/root 4 args: send-mail -i -v user@dest.com LOG: MAIN &........

You need to enable the httpd daemon with monit to actually view the status and control, it's not only for the web interface since the httpd is theONLY way of controlling monit and viewing the status. monit monitor all will also reinstate disabled services if they've timed out too much. Just restarting the service will do nothing to re-monitor a service that monit has stopped monitoring due to too many failures. *Also note that /etc/monit.conf i........

I don't expect this to be solved soon but some of Yahoo's DNS servers are out of whack. I changed the IPs of some nameservers of some domains and now most Yahoo users can't e-mail to those domains! As you can see below by the "No MX or A records for mychangedomain.com", now Yahoo's DNS/mailserver DNS cache is wrong. You would think they would at least have cached the old incorrect records, but instead for some reason their DNS cache has no entry and doesn't seem........

Santrex Review/Scam/Complaint Santrex never provided any working server, I believe it was just a dummy management Solus server because the server said it was booted but never connected to the console. I complained to them and eventually the support admitted the server was not working and to wait for 24 hours. I waited for 4-days, after which they sent an e-mail saying my service was being disabled for SPAM ...(when SolusVM shows 0kb of traffic). Th........

These are the only two I've encountered but here is the low-end and note my story is not at all unique. In my case I was scammed out of money and did not receive any service at all from either company. Santrex Review/Scam/Complaint Santrex never provided any working server, I believe it was just a dummy management Solus server because the server said it was booted but never connected to the console. I complained to them and eventually the support adm........

When migrating away from Plesk I couldn't figure out an easy way to get a straight list of all e-mails, but here is where I found the solution: http://nakuls77.wordpress.com/2008/08/30/details-of-email-ftp-database-users-from-psa-database/ mysql> SELECT mail.mail_name, accounts.password, domains.name FROM mail, accounts, domains WHERE domains.id=mail.dom_id AND mail.account_id=accounts.id; mysql> SELECT CONCAT(mail.mail_name,’@’,domains.name) AS Em........

Convert MBOX Mail files into Maildir using Linux *You need perl an the TimeDate module Get the free Perl script mb2md from the project/author's site: wget http://batleth.sapienti-sat.org/projects/mb2md/mb2md-3.20.pl.gz gunzip mb2md-3.20.pl.gz #remember you need timedate or you'll get this error: ./mb2md-3.20.pl Can't locate........

The first thing you need to remember is not to check from the same host/server itself. This is a silly mistake I made, the reason is that many mailservers and especially postfix are configured to allow relaying from the localhost/same host. If you do that you'll get a false positive. *Make sure you test from another host/system than the mail server itself! telnet yourmailserverhost.com 25 220 Courier (FreeBS........

Basically you should always be 100% sure that whatever IPyour mail server sends out with has reverse DNS/PTR records. Remember that unless you own your IPs then you won't be able to set your own reverse DNS. Even if you were to create a reverse PTR record on your DNS servers it will be ignored. Reverse DNS is queried to pre-assigned DNS servers of your ISP, so therefore you'll need to contact your ISP/Colo/Hosting provider to do a reverse DNS entry. If you don't have........

Dovecot enable SSL (by default it uses an old expired cert if you choose pop3s and imaps as protocols) =================== Create Cert & Key: openssl req -new -x509 -nodes -days 1530 -out server.crt -keyout server.key mkdir /etc/mailssl chmod 700 /etc/mailssl cp server.* /etc/mailssl Edit /etc/dovecot.conf ssl_cert_file = /etc/mailssl/server.crt s........

Create Cert & Key: openssl req -new -x509 -nodes -days 1530 -out server.crt -keyout server.key mkdir /etc/mailssl chmod 700 /etc/mailssl cp server.* /etc/mailssl Postfix SSL config Edit /etc/postfix/main.cf: #SSL stuff smtpd_tls_cert_file = /etc/mailssl/server.crt smtpd_tls_key_file = /etc/mailssl/server.key To make smtps w........

This server was experiencing loads of up to 80 and maxing out the RAM and kmemsize on a CPanel VPS. There were literally dozens if not hundreds of exim processes. I have no idea why exim has such a design that would allow it to consume this much CPU and RAM. Any normal MTA should not be spawning so many processes, it should be processing them in sequence and if it is going to spawn hundreds of processes in response to a large volume of mail, it's better to have a delayed del........

It's basically free bash shell script available from: http://wpkg.org/email2fax/index.php/Main_Page Make sure you have the required tools: libtiff ghostscript mpack/munpack Where you can e-mail your Asterisk box and it will fax it to the phone number in the subject line. The good news ends there, it is fairly undocumented and buggy. Take for example how the documentation mentions you can invoke from the com........

PHP cannot access /usr/bin/opensslI have verified the username that runs the process is able to access /usr/bin/openssl and it does exist but the PHP script is saying it doesn't exist: [code:1:1fd0f3abbe] if (!file_exists($OPENSSL)) { //echo "ERROR: OPENSSL $OPENSSL not foundn"; }[/code:1:1fd0f3abbe] I don't get itI can clearly see the contents of /usr/bin by using the PHP system fu........

E-mail (Thunderbird) with GnuPG encryptionThis is great tool for Mozilla Thunderbird which allows you to encrypt your e-mails so only you and the receiver can view it even if the e-mail is intercepting or obtained by another person. The only small catch is that you of course have to install an extension to Thunderbird and then configure each account you want to use it with. Really it can probably all be done in a few minutes and the effort is worth it.........

African money SCAMI have received countless of these sorts of emails where the person claims to be from an African nation which has a deposed finance minister or some other strange situation which puts millions of dollars at their disposal. The only problem is that they need a partner to get the money out. And they have entrusted only you, yes that's right, to donate your bank account information along with SIN number so they can secretly wire the money over and you w........

Telus Begins Enforcing Bandwidth CapsIt appears Telus has begun to send e-mails out and is planning on enforcing bandwidth caps of only 10gigs/month for their 1.5mbit plan and 20gigs/month for 2.5mbit The state of Canadian ISPs is horrible :( In the east coast, Bell Sympatico will allow you to have unlimited bandwidth and even Aliant will and they have 3mbit for a much more affordable price than our 2.5mbit on Telus. Telus needs to get wit........

You need to jailbreak your phone and inside Cydia you'll find "PushMod" which will allow you to set your mail check time to 1 minute instead of 15-minutes. This is a great mod and has saved me a lot of stress and frustration, the lack of Blackberry style "free push service" makes iPhone less attractive, but this solves that. Apple needs to make mobileme free and have a Blackberry style chat network to compete, I'm not willing to pay for something Blackberry........

Yes, Iadmit I finally got bitten by the hype as much as I can usually see through it all. Keep in mind this review is of the "stock" phone, no jailbreaking yet which is what really unleashes the customizability and whyI bought iPhone. I had better things to say about this phone before buying it, and it is a great phone, perhaps the best on the market by far, if not because of the Mac OS port onto the iPhone and all the apps, etc, etc. With that said........