Viewing email in Linux using postfix's mailq and postcat

When I'm developing using the Drupal Development VM, or checking into email processing on any of my servers, I usually use postfix to handle mail sending. Postfix is simple, preinstalled on most Linux distributions (and easy to set up if not), and is easy enough to use.

Here are the most common commands I use when either developing or troubleshooting email in production:

  • mailq - print a list of all queued mail
  • postcat -vq [message-id] - print a particular message, by ID (you can see the ID along in mailq's output)
  • postqueue -f - process the queued mail immediately
  • postsuper -d ALL - delete ALL queued mail (use with caution—but handy if you have a mail send going awry!)

There are many other helpful commands and scripts to help deal with mail (e.g. deleting all messages to a certain domain, or deleting specific message IDs easily), but these are the main ones I use during day-to-day development and troubleshooting.

Ensuring Drupal email doesn't get sent from a local development environment

It seems most developers I know have a story of running some sort of batch operation on a local Drupal site that triggers hundreds (or thousands!) of emails that are sent to the site's users, causing much frustration and ill will towards the site the developer is working on. One time, I accidentally re-sent over 9,000 private message emails during a test user migration because of an email being sent via a hook that was invoked during each message save. Filling a user's inbox is not a great way to make that user happy!

With Drupal, it's relatively easy to make sure emails are either rerouted or directed to temp files from local development environments (and any other environment where actual emails shouldn't be sent to end users). has a very thorough page, Managing Mail Handling for Development or Testing, which outlines many different ways you can handle email in non-production environments.

However, for most cases, I like to simply redirect all site emails to my own address, or route them to a figurative black hole.

Trouble sending emails from localhost or MAMP? Check your SPF

Email is hard. In fact, it's so hard that I probably have five or so blog posts half-written on this blog that I've abandoned simply because I don't think I could distill them down into something worthy of posting (I like being able to explain things understandably or not at all!).

I don't think there's anyone involved in administering a domain name and email who hasn't gotten burned by SPF (TXT) records at least once. Here's a good overview of how to build a proper SPF record for your domain. SPF records are used by many (if not most) ISPs these days to evaluate whether an email is coming from a particular domain or not.

Email providers like Google, Apple, Hotmail, etc. will evaluate every email they receive against your domain name's ( SPF record, and if the email didn't originate from the IP address specified, or doesn't match up to any other SPF parameters, the email will be silently deleted. And this will cause you to pull your hair out.

Sending emails to multiple receipients with Amazon SES

After reading through a ton of documentation posts and forum topics for Amazon SES about this issue, I finally found this post about the string list format that helped me be able to send an email with Amazon SES's sendmail API to multiple recipients.

Every way I tried getting this working, I was receiving errors like InvalidParameter for the sender, Unexpected list element termination for the error code, etc.

Normally, when sending email, you can either pass a single address or multiple addresses as a string, and you'll be fine:

Configure sendmail on CentOS to allow sending of email from localhost

For some of my Drupal sites and PHP scripts (and shell scripts) that I run on a VPS I manage, I need to simply be able to send outgoing emails from arbitrary email addresses. I could go into all the details of DNS SPF records and MX records here, but that's something you'll need to research on your own. This post simply shows how to install and configure sendmail on a CentOS box to just allow outgoing mail from php's mail() function, the mail command line utility, etc., and only from localhost (

First, install sendmail with $ sudo yum install sendmail sendmail-cf.

Then, configure sendmail by editing the file /etc/mail/ (don't edit the file - we'll auto-generate that after setting things correctly in

Wrapper function for simple drupal_mail() sending in Drupal 7

Email is such a pain (I should know, as I'm currently working on a site that's sending 10-20,000 emails per day to 40,000+ users. Spam prevention, SPF records, bounce handling, abuse reports, deliverability, send rates, etc. are all huge hassles that must be dealt with when handling more than a few hundred emails a day.

For testing, I often like throwing in a quick bit of code to send me or someone else a simple email with a few bits of information when something happens on the site, or to test email addresses or formatting. Therefore I like having a quick one-line function call to send an email. In Drupal 6, there was a handy drupal_mail_send() function that would use some default settings and allow you to quickly shoot off a simple email (not translated, not pluggable, etc., but easy to implement).

Sending Recurring Emails to Thousands, using Simplenews as a Backend

I recently had a rather unique project requirement on one of my sites: I needed to send out a weekly email to hundreds (soon to be thousands) of site users, with the same template each week, but with the latest data from the website.

Basically, what I wanted to do was create a View on my site of the latest 10-12 items, and have that view be sent out to everyone (along with the views header/footer) in HTML (with a plain text alternative, of course), but I didn't want to have to create a new newsletter by hand each week to do this (this is something at which the Simplenews module excels... minus the automation).

After debating over whether I should write my own module to do the dirty work of sending out batches of emails, using modules like Views Send along with Rules and Views Bulk Operations, and some other crazy ideas, I finally found a potent combination for sending out automated weekly newsletters in a highly performant and optimal way, using the following modules:

  • Simplenews (for queuing/sending emails, managing subscriptions)
  • Rules (for scheduling the newsletters)
  • Elysia Cron (for easy cron scheduling and performance)
  • Views (to build the body of the newsletter)
  • Mime Mail (to send HTML emails, and to be able to easily have a custom email-friendly stylesheet)

Drupal Simplenews: Automatically Subscribe New Users to a Newsletter

One of the sites I am setting up requires that all users be subscribed to a certain newsletter (or maybe two, depending on who they are) via Simplenews when they create their accounts (actually, their accounts are automatically created via LDAP... but that's another story).

Looking around, I found this post explaining how you might be able to auto-subscribe new users, and it led me to look up Simplenews' simplenews_subscribe_user() function.

Basically, you can add a line like the following in your custom module's hook_user() function, on the 'insert' $op (for Drupal 6):

Mac OS X Mail App: Deleted Messages Showing in Inbox

Earlier today, when I was working on fixing a few little inconsistencies in my mail inboxes (I currently sync 5 different accounts (with a plethora of email addresses feeding into the various accounts)), deleted messages started showing in some of my inboxes in Mac OS X's built in Mail app. They were greyed out, but not enough so that I could easily distinguish non-deleted messages...

After looking around online for a while, and not finding any fixes for this problem (I get so many emails that showing deleted messages basically makes my inbox unusable), I thought to search the Mail help for an answer.

Show Deleted Messages
Pesky little menu options!

I found a little menu item labeled "Show Deleted Messages" (Command-L keyboard shortcut), which somehow had been selected at some point (I can't think of why I would hit command-l in Mail... but I guess I did). Unchecking that hid the messages. Problem solved!

Use Gmail as an Alternate SMTP/Sending Server

I recently had to find a way to use SMTP for one of my email accounts which only allowed SMTP access through a port that was blocked by my ISP (AT&T), port 25. I decided to use my Gmail account, but realized my name/email would be changed to my gmail account (including the reply-to address). So I set up a new Gmail account for the sole purpose of acting as my SMTP server, and changed the default sending address using the following steps.

  1. In your Gmail account, click on Settings.
  2. Click on the "Accounts and Import" tab.
  3. In the "Send mail as:" section, click "Send mail from a different address."
  4. In the window that appears, put in your name and your original email address.
  5. After you add your original email address, you need to make it your default by clicking the 'make default' button.

Now you can set up your email client to use the Gmail SMTP server instead of your non-functional one, using port 587 with SSL turned on. Your email client should use (for your Gmail account) as the username (just FYI).


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