Practical Computer Advice
from Martin Kadansky
Volume 6 Issue 10October 2012
I Can Receive Email When I Travel, But I Can't Send!

Has this ever happened to you?
  • You take your computer on a trip, or simply across town to a friend's house or coffee shop.
  • You connect it to the internet at that location, either by accessing their wireless network or by plugging in a cable they provide. Or, you start using the cellular phone system for an internet connection through a 3G or 4G mobile broadband card or hotspot or "MiFi."
  • You then open your regular email client program (Outlook Express, Outlook, Windows Mail, or Eudora on Windows, or Apple Mail or Thunderbird or Eudora on Macintosh, etc.), check your email, and see that you can receive new messages just fine.
  • However, you get an error when you try to send email, whether you're composing a new message from scratch or replying or forwarding.
  • When you get back to your home or office (and your regular internet connection), everything returns to normal, and you can send email again without any problems.
  • You may also notice that if you use a smartphone or tablet for email (e.g., an iPhone, Android, iPad, etc.), you have no problems receiving or sending, whether you're at home or away, as long as your device can get internet access.
This is a growing problem for people who move their computers between different internet connections and use regular email programs. On the other hand, you've probably never experienced this problem if you use webmail (accessing your email using an email web site through a web browser like Internet Explorer or Mozilla Firefox or Google Chrome or Safari).

The good news is that this problem can usually be fixed by adjusting your email program's settings.

The bad news is that this is a moderately technical topic. On the bright side, there are only 3 specific email settings that you need to focus on.

How to solve it
If you're already familiar with how to adjust the settings in your email program, then here are the most likely solutions in a nutshell:
  • Try a different SMTP (outgoing) port number: If your email provider supports SSL, try changing the port from 25 (the default) to 465 and turning on the SSL option. If SSL is not supported (or for some reason it doesn't work), try port 587 and leave the SSL option off. These are the standard port numbers; if your email provider uses other numbers, use theirs instead.
  • Try turning on the SMTP authorization option.
  • If your email address uses your own domain (e.g.,, find out the SMTP server name(s) and port number(s) for your domain hosting company's email server (probably something like with port 587 or 465) and try them.
  • If you just can't get this to work and your email provider offers webmail, a free (but somewhat awkward) workaround is to use that webmail when you're on the road instead of your email program.
  • As a last resort, if spending money to solve this is worth it to you, consider a paid "on the road" SMTP service. See "Where to go from here" (below) for suggestions.
  • If you start using SSL and your antivirus program is set to scan your incoming or outgoing email, you may start seeing errors when the encryption that SSL provides unfortunately prevents your antivirus program from scanning those messages. Check your antivirus program's documentation for ways to solve this.
You'll probably have to "fiddle around" with these settings before you find a combination that works, so I recommend that you write everything down:
  • Your email program's settings before you make any changes.
  • The new settings that work on the road and where you were located.
  • The new settings that work at home.
  • How to find those settings in your email program so you'll know where to look in the future.
Ideally, you'll find a combination of settings that works both at home and on the road, but you may need to change your settings for use when traveling and then change them back when you return home.

What does all that terminology mean?
If you're not familiar with email terminology like this, here are some definitions:
  • SMTP server name: This is the name of the email server responsible for sending your outgoing email. Each company providing email services has a different server name. For example, "" is the SMTP server for Comcast. Every email provider (Comcast, Verizon, RCN, Gmail, AOL, etc.) has a different SMTP server name. (SMTP stands for "Simple Mail Transfer Protocol.")
  • SSL: This is an option that means you want to protect (encrypt) your email username and password when your email program talks to the server. Certain port numbers (see below) imply that the SSL protocol will be used, and others imply that it won't. Even though it's a great idea, only some email servers support SSL. (SSL stands for "Secure Sockets Layer.") You may also see TLS (Transport Layer Security), which is a newer protocol that some companies offer in addition to SSL.
  • SMTP port number: This tells the SMTP server how to handle the outgoing connection, including whether or not SSL will be used. The most common SMTP ports that don't use SSL are 25 and 587; some companies use 26, others use 2525. The most common SMTP port with SSL is 465.
  • SMTP authorization: This is an option that makes your email program supply your email address and password every time it sends a message. Some SMTP servers require this to ensure that only authorized users send messages on their networks. This changes your computer's conversation with the SMTP server from "Hi, I want to send this email, just trust me that I'm a customer of your company" to "Hi, I want to send this email, and here's my proof that I'm a current customer."
  • POP server name, IMAP server name: Although not related to problems with sending, for completeness these are the names of the email servers responsible for giving your incoming email messages to your email program, depending on which of these two protocols you choose, and they have corresponding SSL and non-SSL port numbers as well. (POP stands for "Post Office Protocol," IMAP stands for "Internet Message Access Protocol.")
Why do email providers refuse to let me send messages because of these settings?
This is all about increasing security and blocking potential sources of spam. While receiving your email has always required your email address and password (which authorize you to access your account), for many years the standard way you sent messages using a regular email program used generic and somewhat anonymous settings: SMTP port 25 with SSL off and no SMTP authorization.

Unfortunately, spammers and hackers have exploited port 25 so much that in recent years many email providers and internet service providers (ISPs) have started to assume that senders using these generic settings are probably spammers, and have tightened up their requirements for sending email, especially when those senders aren't physically connected to their networks.

That's why, for example, if you have Comcast internet service at your home or office (and you use a Comcast email address), if you take your computer to a hotel that uses Verizon internet service and your email program isn't set up properly, you may find that you can't send email at that hotel. It isn't that Verizon is blocking your message because it's sent from a Comcast address, it's that Comcast sees your address being used to send email via a non-Comcast physical connection with generic (and therefore suspicious) settings and rejects it.

How to gather the information you'll need to try to fix this problem
To find out your SMTP server's permitted settings, I suggest that you:
  • Do a google search for: companyname smtp (replace "companyname" with your email company's name, e.g., Comcast, Verizon, Earthlink, etc.)
  • Go to your email provider's web site and look for "email settings" or "POP and SMTP server info"
  • Call your email provider and ask.
These are the 3 email settings you're looking for:
  • SMTP server name(s) for both non-SSL and SSL connections
  • SMTP port number(s) for both non-SSL and SSL connections
  • Whether your SMTP server requires SMTP authorization or not
Note: These settings can be a bit interrelated. For example, most companies use the same server names for non-SSL and SSL connections, but a few use different ones.

Your email account password: No, you probably don't type it in; yes, you do have one
When I mention the need to enter the password for an email account, many clients tell me that they get their email every day without typing a password, so they must not have one.

Rest assured, every email account has a password, and it must be supplied every time your incoming email messages are fetched, and every time you send email if you're using SMTP authorization. Your email software doesn't ask you for it because back when it was set up you probably typed it in once, and it has remembered it for you ever since.

When you put your computer on a different internet connection, you may get errors when sending email. In order to try to fix this problem, you need to:
  • Find out what settings your SMTP server supports.
  • Find out what SMTP settings your email program can handle.
  • Adjust your email program's SMTP settings appropriately.
  • Test to make sure you can still receive and send email at home.
  • Test to see if you can receive and send email when you're traveling.
  • Keep careful track of the settings that work.
  • Be prepared for unexpected problems that may come up.
Where to go from here
How to contact me:
phone: (617) 484-6657

On a regular basis I write about real issues faced by typical computer users. To subscribe to this newsletter, please send an email to and I'll add you to the list, or visit

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Copyright (C) 2012 Kadansky Consulting, Inc. All rights reserved.

I love helping people learn how to use their computers better! Like a "computer driving instructor," I work 1-on-1 with small business owners and individuals to help them find a more productive and successful relationship with their computers and other high-tech gadgets.

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