|Home||Pauline's Pages||Howto Articles||Uniquely NZ||Small Firms||Search|
|Howto Send Email from Anywhere|
This started with a request to help set up BT Total Broadband for one of my customers who needed to do a lot of work from home. This led to me gaining a lot of information and understanding about sending email, in particular about the restrictions imposed by many ISPs and network providers and some ways I have discovered to how to get round them while on the move. My main page covering Global Communications and Computing had identified some of the issues but this page will go into much greater depth. It will mostly cover send Email consistently and reliably whilst on the move with a laptop but will also cover some of the other methods available for the use with a laptop or desktop through a single service providers different from those providing ones email services, the original problem I set out to solve. There is a bit about BT Total Broadband in my Diary Page where this article was drafted.
Firstly lets consider how is email sent and then why do ISPs want to restrict its use. The standard and almost universal way email is sent around the world involves the use of the Simple Mail Transport Protocol (SMTP) . Every standard email program takes the message you want to send and transfers it to a SMTP server which then sends it onto the Internet where it eventually ends up in one or more mailboxes. The mail server is usually provided by the ISP and has a 'normal' internet address and mail which is to be sent out is sent by convention to port 25. For those who do not have any idea what a port is then an analogy is that an internet address say mail.fasthosts.com is like a telephone exchange and the port is like an extension. The use of many ports is historically well defined, web servers are on port 80 and SMTP servers on 25 whilst ports around 139 are to do with file transfers.
Spam is one of the main problems facing the Internet rating alongside Viruses and other malware. The restrictions introduced by ISPs mainly result from their obligations to control spam. One of the responses to the increase in spam email is that ISPs try to ensure that all email sent from their domain can at least be traced back to the sender. This way if a user of an ISP starts spamming, the ISP can quickly close their account. If this is not done and an ISP gets known as a source of spam he will be blacklisted and many ISPs will block all email from blacklisted sources often without even notifying the recipients that emails have been blocked. This is a disaster and ISPs are becoming paranoid about the risks of being blacklisted. New laws also mean that ISPs also have to keep a record of emails which are sent.
How do ISPs trace email that originates from their domain? In the days of dial up the ISPs used to check the caller ID of the phone and only allow access to their SMTP server for their customers calling in on one of their access numbers. The technique is similar for broadband which can be traced to the particular telephone line and ADSL account used for access. This enables the identification of the source of spam but only allows for users their ISP to access to send email from a single place via broadband or via a dial up telephone connection. It prevents any sending of email when using a mobile phone and GSM or 3G data connection, a broadband connection from any other site or WiFi hotspot.
In some cases you can use the SMTP server of the ISP who is providing the connection – at home by broadband connection is provided by Tiscali but my web sites and email by Freezone and Fasthosts. I send an email with an address of say firstname.lastname@example.org via smtp.tiscali.co.uk and it works fine for my desktops at home as a solution. When I use a laptop via the mobile phone and a Vodafone GSM data connection I swap to the vodafone SMTP server smtp.vodafone.net and so on. However the average WiFi hotspot does not provide a SMTP server at all as it would be a magnet for spammers. Even use of the SMTP server of the Service you are using does not always work as some ISPs limit use of their SMTP servers to messages from their own domain by checking the 'From:' address field and will not automatically relay messages that don't come from their domain. If you get an error message saying "relaying denied" or "relaying not allowed", then your ISP has put these measures in place.
Authenticated SMTP servers are one answer to access from many places. Many ISPs SMTP servers for their clients to access via other other networks where you are Authenticated by a username and password rather than your access route. This allows you to send emails from home, WiFi access points, mobile connections and other broadband connections without having to change the SMTP server address in your email package. These are often not well known or publicised but they do exist for the services that interest me here namely; Freezone, Btconnect (the BT business service) and Fasthosts (but only for their Advanced mailboxes where it is called roaming). They may exist for Btinternet, the home service as well but I have looked for or found it yet. The following give links from which the information can be gleaned.
This is however not the end of the story as many ISPs and network providers do not like you to use their networks to send email which could be spam even if it is not through their SMTP servers and try to prevent it. I have started to come across this problem whilst traveling and examples are Xtra in New Zealand and many of the mobile operators including parts of the Vodafone worldwide system. So how do they control email whilst you are using their network? The easiest (and only really practical) method is to just force all emails to go via their SMTP server or as it is perhaps more correctly known MTA (Mail Transport Agents, the underlying programs that transfer emails round the world). Now as discussed above MTAs have traditionally listened on port 25, and that is the industry standard. So what most ISPs do is prevent connections to port 25 to propagating freely on the internet and either block it, divert any traffic to port 25 to their own SMTP server or in some cases check the email addresses used to verify it against a list of those which have been authorised in advance. An example of an ISP that allows pre-authorisation on their SMTP servers is BTconnect, the commercial side of BT.
A number of firms have grown up which provide an authorised SMTP service such as AuthSMTP and SMTP.com for those whose ISPs do not offer a service and they have worked out a solution to the problem - they set up their servers to also allow access on other port numbers. The common ports which are used are 225 and 2525 because they are easy to remember and they also use ports such as 23 and 26 which are normally reserved for other services such as Telnet which can not be globally blocked. They both offer diagnostic utilities which will check which ports are blocked and open or suggest how to check yourself so you can chose a suitable port. for example telnet smtp.com 2525 will check if port 2525 is open and gets through your firewall. It looks as if AuthSMTP offers more ports and is marginally cheaper and offers a fuller service but I have not tried either. Fasthosts Roaming (authenticated) SMTP also offers the ability to select port 225 which is less common and less likely to be blocked. I contacted Freezone and they suggested using 587 which is an AOL email port which their SMTP server will accept. I found using port 587 allowed me to use the Freezone SMTP server whilst on the Cunard Queen Mary 2 cruise ship when I accessing through Thunderbird under Linux so I know it works.
|Fasthosts||Freezone||BTconnect (Business)||BTinternet (home)||Tiscali|
|Authenticated Server||On Advanced mailboxes only||Available||Available||Available||Not Available|
|SMTP Server||smtp.fasthosts.co.uk [or mail.fasthosts.co.uk]||auth-smtp.freezone.co.uk||smtp.btconnect.com [or mail.btconnect.com ?]||
mail.btinternet.com [or smtp.btinternet.com ]
|Authentication Username||Same as pop account||fzxxxxxxx if you have an old account or preferably email@example.com||Same as pop account||BT Yahoo Username||-|
|Same as pop account||Your fzxxxx password if you have an old account or your admin account password if you have a domain||Same as pop account||BT Yahoo Password||-|
|Ports available||25 and 255||25 and 587||25 and 587??||25 and 587||25|
|Use for other email accounts (Email relay)||No - only the email address of the Advanced Mailbox can be used on mail sent||No limitations at present||With telephone registration of each address on other domains||With Internet registration of each address on other domains||No limitations at present|
Many PDAs have a simple email set up which does not support changing the port. If you do not have a field in the email set-up to enter the Port number, the case on many PDAs and phones, try entering something like "smtp.mailserver.com:2525" (without the quotation marks), into the "Outgoing Mail" field. This way, the colon specifies that 2525 is the port you wish to use without the explicit use of a field which will work in many applications.
BT Total Broadband is an example of a ISP that does not allow use of their SMTP server. As the original task which led to this page was setting up to use BT Total Broadband it is appropriate to take it as an example here of the sort of approach one may have to use. If you've got a non-BT e-mail address which you want to keep using from an ISP which does not have an Authenticated SMTP server then you your choices are:
The first two have the advantage that they will allow you to and send email almost anywhere if you use a laptop whilst the third only solves the problem for a desktop on BT Total Broadband.
This is likely to cost no more than using a dedicated service such as AuthSMTP and has many advantages including unlimited numbers of emails.
Fasthosts email plus package is £14.99 a year (plus VAT) and offers two Advanced mailboxes with separate Authorised (Roaming) SMTP access plus many other features namely
You do not have to use the new addresses immediately because you can set the reply to address of your old email in your outgoing mail settings and set up a forwarder on the mailbox to divert any email to that account to your old one.
Freezone Internet where this site (pcurtis.com) is hosted offer similar facilities for £0.99 a month (plus VAT?) with a FREE domain name but no alternative SMTP port other than 587 .
Both need a Domain name to be registered but that gives a fixed address for one whatever provider you use in the future. Domain registration is included with Freezone and works out at £5.95 every two years (plus VAT?) for Fasthosts through their subsidiary UKReg . Setting up an email only account is my longer term recommendation to my client.
These may offer some advantages if you do a lot of traveling and will probably be quicker to respond to developments in the spammer war. They already have multiple ways round the port 25 issue. They are expensive but can also deliver an additional audit trail on the emails you have sent and they argue they are more reliable and less likely to be on Blacklists than a normal ISP's Authenticated SMTP server. The two best known are AuthSMTP and SMTP.com . I have not used either as I personally favour the solution above.
The need for pre-registration with BT Broadband's outgoing mail servers comes about because, even when authenticated themselves, they will not normally allow you to send e-mail which looks as if it comes from a non-BT e-mail address as they check your FROM: headers. They do however allow you to specify in advance what non-BT addresses you want BTinternet to allow. This is poorly documented and the way forwards I offer originates from information I located at http://www.pdoc.co.uk/btbroadband.shtml .
First specify the emails addresses the want the BT Broadband SMTP server to allow:
I am not sure where to put this discovery so I have left it in with other facts about BT Total Broadband. All the communications for a BT 'home' Account ( @btinternet.com addresses) is routed through the address they set up for you on BT Yahoo! so it is important to check it or include it in the emails you download. I accessed that initially by the web mail interface, as will many home users, then set up an account in Outlook along with the other two accounts. Interestingly I found that once I had opened it and read it using webmail it would not download – this might be because I had specified leaving a copy on the server but I have not had this with any other webmail system but is something to watch for.
|Copyright © Peter and Pauline Curtis
Content revised: 30th August, 2007
More on Port 587 added October 2008
Last minor change: 22 nd November, 2009