I Can Read My UF E-Mail at Home, But Can't Send

Contents

Background: The Problem
The Essential Facts
How-To: Configuring Outlook Express
How-To: Configuring Thunderbird

I use GatorLink E-mail, and, when I'm using my computer at home, I can read my messages OK, but when I try to send a message, I get an error, and the message never goes out.

OR: I have my laptop's e-mail program set to use SMTP.UFL.EDU (or my department's SMTP server) as my outgoing mail server. But my Internet Service Provider has started blocking all outgoing mail servers except for their own. Now, when I'm at home, my mail won't go out unless I use my ISP's server. But when I bring my laptop to campus, or go travelling, I end up having to reconfigure my e-mail program, because everyplace seems to have rules blocking outbound e-mail! What can I do?

E-mail is a complex system, involving not only your computer, but also an "incoming mail server" (which holds your incoming e-mail until you ask for it), and an "outgoing mail server," which receives outbound mail you send, and routes it to its destination. This "outgoing mail server" is also known as an "SMTP" (Simple Mail Transfer Protocol) server. In addition, each server may have multiple "ports" by which you can communicate with it. Think of "ports" like the various teller-windows in a bank: the bank (server) has only one address; but some kinds of business are only done at "Teller A" and other types of transactions have to go to "Teller B." Similarly, a server may have one name, but accept different types of "transactions" on different "ports."

In order to help restrict "spam," "worms," and other malware which often propogate via e-mail, many Internet Service Providers (ISPs) have begun to require that all outbound e-mail (on the "default" SMTP port [25]) use only their "official" server(s). However, this practice may cause people who were formerly able to send e-mail from home with no problem, to suddenly not be able to send outgoing mail.

It also severely complicates life for users of mobile/laptop computers, who frequently connect to different networks, requiring changes to their e-mail program configuration with each change of location.

Fortunately, many ISPs, including UF's central e-mail servers, support an alternative means of e-mail submission; the Message Submission Port, port number 587. In fact, according to the Internet Standard describing this method (RFC2476), port 587 is actually the preferred port for submitting outgoing e-mail to an SMTP server. It is specifically designed to be the entry point for new messages, and requires "secure authentication" (either TLS or a authentication mechanism that doesn't reveal the user's password). Unlike SMTP (or SMTP over SSL) the Message Submission port doesn't accept messages from unauthenticated sources, helping to protect networks and users from malicious e-mail.

After configuring your e-mail program to send outbound mail via the Message Submission port, you will probably find that you are prompted for your username and password the first time you send a message during each e-mail session. Generally, after you authenticate for the first outbound transmission, your system will remember your credentials as long as you don't exit/quit the program.

The Essential Facts:

UF Outgoing E-mail Host	`smtp.ufl.edu`
Message Submission Port	`587`
Authentication Required?	Yes, Username & Password
Connection Encryption	TLS (note; SSL is not TLS)

The remainder of this article will show how to configure two common e-mail programs, Microsoft Outlook Express, and Mozilla Thunderbird, to use the Message Submission port. Other e-mail programs will generally be similarly configurable.

How-To: Configuring Outlook Express

You configure Microsoft Outlook Express to use Message Submission port 587 via the following procedure:

From the main Outlook Express menubar, select Tools
From the Tools dropdown menu, select Accounts...
On the Internet Accounts panel, select the Mail tab
Highlight the entry for your UF e-mail account (it may be labeled "imap.ufl.edu")
Click the Properties button
In the <your e-mail accountname> Properties dialog box, click the Servers tab
In the Outgoing Mail Server section, click the "My server requires authentication" checkbox
Click the Settings... button
Click the Log on using radiobutton
Make sure your username (for the server you use to send mail) is entered in the Account name: field
Click the OK button
You will be back on the main <your e-mail accountname> Properties dialog box. Click the Advanced tab
Set the Outgoing Mail (SMTP): field to 587
Click the Apply button
Click the OK button
Click the Close button

How-To: Configuring Thunderbird

You configure Mozilla Thunderbird to use Message Submission port 587 via the following procedure:

From the Thunderbird main menu, select Tools
From the Tools dropdown menu select Account Settings...
In the Account Settings dialog box, from the left-hand pane, select "Outgoing Server (SMTP)". You may have to scroll down in this panel to find this selection, depending on how many accounts you have configured.
The Outgoing Server (SMTP) Settings dialog box is shown below.
- Enter your preferred outgoing mail server in the Server Name: field. The example above uses UF's central ("GatorLink") server.
- Enter "587" as the Port number (as shown above)
- Check the "Use name and password" checkbox
- Enter your username for this server in the User Name: field.
- Check the TLS radiobutton.
Click OK.

For Further Assistance

If you need additional assistance in configuring your e-mail program, please contac the UF Computing Help Desk at 352.392-HELP, e-mail:<helpdesk@ufl.edu>.

Your Comments are Welcome

We welcome your comments and suggestions on this and all CNS documentation. Please send your comments to:

UF Computing & Networking Services
112 SSRB, University of Florida
P.O. Box 112050
Gainesville, Florida 32611-2050

Phone: (352) 392.2061
E-mail: editor@cns.ufl.edu