Sending texts from your computer is extremely useful in dozens of different situations. Perhaps you lost your phone and need to send a message to someone; maybe you’re over your monthly text limit and still need to get in touch with your friends; or what if you just hate typing on a tiny keyboard or lack cellular service? I know my living room might as well be a black hole when it comes to coverage. 

If you simply want to send an SMS to any mobile phone, there’s no need to use third-party services. You can do it right from your email client. Instead of using a service you don’t know or trust, you can deliver a short email in the form of a text message by using an email to SMS gateway. So long as you know the person’s phone number and the name of their service provider, you can easily find the appropriate gateway address that will forward your message.

Don’t know what mobile carrier your friend uses? Find out here.

For quick reference, I’ve put together a list of some of the most common U.S. service providers and their corresponding gateway addresses below. Annoyingly, there are different addresses for regular messages (SMS) and those that include photos and other media (MMS).

In either case, sending a message is easy. Just compose an email like you normally would, but rather than entering the person’s email address in the recipient box, simply insert their 10-digit phone number with the appropriate @gateway address behind it. Then, hit send.

*For T-Mobile, include “1”, which is the U.S. country code, before the phone number. To find SMS gateways for carriers not listed here, and carriers in other countries, check this list on Github.

To ensure that this process works, you should limit your messages to less than 160 characters. If you go over this 160 character limit, the message will be sent as an MMS rather than a SMS, which sometimes requires a different gateway address. Furthermore, although this method is entirely free for you the sender, standard messaging rates may still apply to the person receiving these messages. No third-party service will have access to your telephone number, or the person you’re messaging, and replies will go directly to your email inbox. This process also makes it easy to send the same text to multiple people, since you can add as many addresses as you like to the recipients box.