email

Sending Emails? Send them from Linux Terminal

Suparna Ganguly — Wed, 20 Oct 2021 16:00:00 +0000

Does your job require sending a lot of emails on a daily basis? And you often wonder if or how you can send email messages from the Linux terminal.

This article explains about 6 different ways of sending emails using the Linux terminal. Let’s go through them.

sendmail Command

Use the sendmail command to send emails to one or more people at once. Sendmail is one of the most popular SMTP servers in Linux. You can easily send emails directly from the command line using the sendmail command. To route the information, the sendmail command makes use of the network configured on your system.

Let’s execute the following commands to create a file having email content.

cat /tmp/email.txt

Subject: Terminal Email Send

Email Content line 1

Email Content line 2

The Subject will be the line used as a subject for the email.

Now, to send the email, use the following syntax.

sendmail user@example.com  < /tmp/email.txt

mail Command

Just like Sendmail, you can use the mail command for sending emails from the terminal. Use the below-given command for this purpose.

mail -s "Test Subject" user@example.com < /dev/null

Here -s defines the email subject.

To send an attachment included within the email, type the below-mentioned line.

mail -a /opt/backup.sql -s "Backup File" user@example.com < /dev/null

Here -a is used to include attachments. If yours is a Debian-based distro, use -A because it uses the mailutils package.

If you have to send emails to multiple recipients at a time, add comma-separated emails in the following manner.

mail -s "Test Email"  user@example.com,user2@example.com < /dev/null

mailx Command

The GNU Mailutils is a combination of multiple utility packages. All Mailutils can operate on mailboxes starting from UNIX maildrops, maildir, and all the way up to remote mailboxes. These mailboxes are accessed with IMAP4, POP3, and SMTP. Mailutils is made for developers, regular Linux users, and system administrators.

For the installation purpose, use the following command.

sudo apt install mailutils

The mailutils package is mainly made of 2 commands, mail and mailx, and they both function in a similar manner.

Go to Full Article

FOSS Project Spotlight: Tutanota, the First Encrypted Email Service with an App on F-Droid

Matthias Pfau — Thu, 11 Oct 2018 12:00:00 +0000

by Matthias Pfau

Seven years ago, we started building Tutanota, an encrypted email service with a strong focus on security, privacy and open source. Long before the Snowden revelations, we felt there was a need for easy-to-use encryption that would allow everyone to communicate online without being snooped upon.

Figure 1. The Tutanota team's motto: "We fight for privacy with automatic encryption."

As developers, we know how easy it is to spy on email that travels through the web. Email, with its federated setup is great, and that's why it has become the main form of online communication and still is. However, from a security perspective, the federated setup is troublesome—to say the least.

End-to-end encrypted email is difficult to handle on desktops (with key generation, key sharing, secure storing of keys and so on), and it's close to impossible on mobile devices. For the average, not so tech-savvy internet user, there are a lot of pitfalls, and the probability of doing something wrong is, unfortunately, rather high.

That's why we decided to build Tutanota: a secure email service that is so easy to use, everyone can send confidential email, not only the tech-savvy. The entire encryption process runs locally on users' devices, and it's fully automated. The automatic encryption also enabled us to build fully encrypted email apps for Android and iOS.

Finally, end-to-end encrypted email is starting to become the standard: 58% of all email sent from Tutanota already are end-to-end encrypted, and the percentage is constantly rising.

Figure 2. Easy email encryption on desktops and mobile devices is now possible for everyone.

The Open-Source Email Service to Get Rid of Google

As open-source enthusiasts, our apps have been open source from the start, but putting them on F-Droid was a challenge. As with all email services, we have used Google's FCM for push notifications. On top of that, our encrypted email service was based on Cordova, which the F-Droid servers are not able to build.

Not being able to publish our Android app on F-Droid was one of the main reasons we started to re-build the entire Tutanota web client. We are privacy and open-source enthusiasts; we ourselves use F-Droid. Consequently, we thought that our app must be published there, no matter the effort.

When rebuilding our email client, we made sure not to use Cordova anymore and to replace Google's FCM for push notifications.

Go to Full Article

Cleaning Your Inbox with Mutt

Kyle Rankin — Tue, 28 Aug 2018 12:00:00 +0000

by Kyle Rankin

Teach Mutt yet another trick: how to filter messages in your Inbox with a simple macro.

I'm a longtime Mutt user and have written about it a number of times in Linux Journal. Although many people may think it's strange to be using a command-line-based email client in 2018, I find a keyboard-driven email client so much more efficient than clicking around in a web browser. Mutt is extremely customizable, which presents a steep learning curve at first, but now that I'm a few decades in, my Mutt configuration is pretty ideal and fits me like a tailored suit.

Of course, as with any powerful and configurable tool, every now and then I learn of a new Mutt feature that improves my quality of life dramatically. In this case, I was using an email system that didn't offer server-side filters. Because I was a member of many different email groups and aliases, this meant that my Inbox was flooded with emails of all kinds, and it became difficult to filter through all the unimportant email I wanted to archive with the emails that demanded my immediate attention.

There are many ways to solve this problem, some of which involve tools like offlineimap combined with filtering tools. With email clients like Thunderbird, you also can set up filters that automatically move email to other folders every time you sync. I wanted a similar system with Mutt, except I didn't want it to happen automatically. I wanted to be able to press a key first so I could confirm what was moving. In the process of figuring this out, I discovered a few gotchas I think other Mutt users will want to know about if they set up a similar system.

Tagging Emails

The traditional first step when setting up a keyboard macro to move email messages based on a pattern would be to use Mutt's tagging-by-pattern feature (by default, the T key) to tag all the messages in a folder that match a certain pattern. For instance, if all of your cron emails have "Cron Daemon" in the subject line, you would type the following key sequence to tag all of those messages:


TCron Daemon

That's the uppercase T, followed by the pattern I want to match in the subject line (Cron Daemon) and then the Enter key. If I type that while I'm in my Mutt index window that shows me all the emails in my Inbox, it will tag all of the messages that match that pattern, but it won't do anything with them yet. To act on all of those messages, I press the ; key (by default), followed by the action I want to perform. So to save all of the tagged email to my "cron" folder, I would type:

Go to Full Article

Achieving Inbox Zero

Shawn Powers — Tue, 16 Jan 2018 23:13:15 +0000

by Shawn Powers

See how Google Inbox helps Shawn reach his quest for "inbox zero".

I've never been able to accomplish "inbox zero" for more than a couple hours. Part of it is due to poor organization on my part, and part of it is due to being too busy. The problem isn't that I get more email than I can handle (although that's probably true, I get a couple hundred messages a day), it's that most messages require a followup that I can't accomplish immediately. I've tried to move items I need to handle later quickly into a to-do list like Wunderlist, but it's an extra step that takes more time, so I just let things pile up in my inbox.

For some reason, I recently decided to try Google Inbox. It's not a new offering from Google, but I think it's matured since I originally tried it years ago. See, Google Inbox allows me to keep inbox zero with minimal effort and zero guilt. Here's the premise:

When an email comes in, a quick swipe to the right will archive it. It's not even a click—just a swipe and it's gone.
If I need to open it, I can tap it, then click a check box to archive it if I don't need to follow up.
Here's the beauty. If I need to follow up on a message, even if it's just something interesting I want to read later at my leisure, I can snooze it. In the screenshot, you can see the options for snoozing, and they work perfectly.

The idea of snoozing email isn't new. I remember using "boomerang" for such a thing a few years ago. But Google Inbox has integrated the snooze and archive features so well that I can clear my inbox completely in moments and not worry that I've forgotten something. In fact, the snooze feature works much better than just leaving stuff in my inbox, because it actually comes back to my attention after the snooze period instead of falling off the end of my inbox.

Again, it's not a new product, but it has revolutionized my life. You can check it out without messing up your regular Gmail inbox by logging in here in a web browser or by downloading the mobile app. You won't regret it!

Go to Full Article

The Peculiar Case of Email in the Cloud

Shawn Powers — Mon, 03 Oct 2016 12:00:00 +0000

by Shawn Powers

Most of the time when I start a project, or spin up a virtual server, it's done in my own basement "server farm". Not too many years ago, if I wanted those services to be public, I'd simply port-forward from my static IP into my personal machines. Or, perhaps I'd set up a name-based virtual host as a reverse proxy if I needed to expose a Web app. The nice thing about hosting projects locally is that when I need to send e-mail messages (usually error notifications), I simply can send them through my ISP's SMTP server. Granted, that's gotten a little more complex through the years, as ISPs are starting to lock down their mail servers and relay mail only for valid domains, but that just means I have to register my static IP properly. It works nicely.

The problem is, the issues I've had with my office Internet connection during the past year really have forced me to reconsider how I host public-facing services. I've been forced, by necessity, to spin up cloud instances and host my numerous projects remotely. I'm actually rather thankful for the need, because although it's not free to host projects remotely, it's fairly inexpensive and much more convenient. I still have my Raspberry Pi colocated in Austria for free (thanks again, Kyle Rankin, for pointing me to that awesome service!). Unfortunately, the Raspberry Pi isn't powerful enough for many of the crazy things I try on-line. It struggles, for instance, to host MySQL. So my main "project" server is a Google Compute instance that I end up paying about $15/month to keep active. That's not cheap, but I actually think I might be able to turn off one of my ESXi machines at home now, and I suspect it uses more than that in electricity.

The Problem

The problem with Internet-hosted servers is that the lack of a usable SMTP relay makes e-mail very difficult. Yes, it's possible to install Postfix as a full-blown e-mail server, but I have no desire to worry about securing my own e-mail server from attacks attempting to use me as a SPAM relay. And although installing a non-relaying e-mail server certainly is possible, I've found that unless you configure SPF records, MX records and get particularly lucky, e-mail sent from a cloud instance often never arrives at the destination. This is especially true if you spin up servers on the fly.

The truth of the matter is, the only reason I want e-mail in the first place is so I can get notifications from my servers when something goes wrong. I don't ever need to reply to the e-mails. I don't really care where the e-mails come from (address-wise). I just want to have confidence that my notifications will get to me!

Go to Full Article

Sending Email with Netcat

Pete Vargas Mas — Tue, 20 Apr 2010 17:04:52 +0000

by Pete Vargas Mas

Is it possible to send an email from a host that has no email client software installed? As long as you have netcat, of course it is!

Netcat (/usr/bin/nc on Red Hat Enterprise Linux systems) is a simple utility for reading and writing data across TCP/UDP connections. It's often used for testing and debugging network connections. In its most basic usage, netcat allows you to feed a stream of data to a specific port on a specific host, which is perfect for our purpose here. Check the netcat man page for more information on it's various features. There are also sample scripts under /usr/share/doc/nc-*/. If netcat is not installed on your Red Hat Enterprise Linux, CentOS or Fedora system, you can install it with the command yum install nc.

What we will be doing with netcat is using it to feed a stream of data to port 25 (SMTP) on a mail relay, making it believe it's talking to a regular email client. In order to do this, we first need to figure out what our email server expects to see from a client. This can be done by connecting via telnet to our SMTP relay host and issuing the correct SMTP commands, as in the following example:

   [user@host]# telnet smtp.domain.com 25
   Trying 192.168.0.1...
   Connected to smtp.domain.com (192.168.0.1).
   Escape character is '^]'.
   220 myrelay.domain.com ESMTP
   HELO smtp.domain.com
   250 myrelay.domain.com
   MAIL FROM:
   250 sender  ok
   RCPT TO:
   250 recipient  ok
   DATA
   354 go ahead
   From: [Alice Hacker] 
   To: [Bob Smith] 
   Date: Mon, 12 Apr 2010 14:21:26 -0400
   Subject: Test Message

   Hi there!
   This is supposed to be a real email...

   Have a good day!
   Alice


   .
   250 ok:  Message 222220902 accepted
   QUIT
   221 myrelay.domain.com
   Connection closed by foreign host.
   [user@host]#

Note that the userid part of the "From" address does not have to contain a valid userid, only a valid domain name. You will have to replace "smtp.domain.com" with a valid SMTP relay that allows relaying from your host. Generally, experienced admins will disallow relaying from unknown hosts to discourage spam. Additionally, the body of the email (everything after the "DATA" command) is ended by sending a blank line, followed by a line with a period (.) on it by itself.

Now that we know what the remote server expects to see, we can craft a text file with our SMTP commands and the message to be sent. The recipients mail server will expect the date to be in a particular format.

Use the command:

date '+%a, %d %b %Y %H:%M:%S %z'

To generate a date string that resembles:

Mon, 12 Apr 2010 14:21:26 -0400

The contents of your message file should resemble this example:

Go to Full Article

Wave Goodbye to E-mail?

Shawn Powers — Thu, 15 Apr 2010 14:46:06 +0000

by Shawn Powers

Late last year, getting a Google Wave invite was reminiscent of getting a Cabbage Patch Kid in 1983. It was the newest gizmo everyone just had to have. As a geek, I was one of the kids begging the loudest. Thankfully, one of our readers from across the pond (Paul Howard, thanks!) sent me an invite, and I cleared my schedule for the product that was going to change the way I communicate. Only, it didn’t.

I’ll admit, some of the reasons are not Google’s fault. First, off, it wasn’t even in beta yet. I also didn’t really have anything I wanted to communicate with anyone. Even with those two things in mind, I did expect it to be fun to experiment with. Quite frankly, it seemed more cumbersome than helpful.

In watching the demonstrations on the Google Web site, it seems apparent Google Wave was designed to solve some problems we’ve all faced in e-mail. Where I think Google may have gone wrong, however, is in trying to solve a problem with additional technology that really we’ve all learned to manage anyway. Sure, Google Wave allows conversations to take place in one section, so everyone can see what’s going on, but we’ve all solved that years ago with “reply all” and “forward”. Yes, Wave allows for embedded photos, videos and so on, but let’s be honest, we’ve all been attaching files and/or links for years.

Google Wave Screenshot

So what do you think? Am I off-base with my assessment? Is Google Wave changing the way you communicate? If so, I’d love to hear about it. You’ll have to send me an e-mail though (or comment here), because even though I got my Google version of the Cabbage Patch Kid, mine is still in the box.

Go to Full Article