ISP is an abbreviation for Internet Service Provider. This is a business that provides connection to the Internet. Common examples are Telus (adsl and dial-up), cable providers (Shaw) as well as a myriad of others.
Internet Service Providers are blocking the sending of e-mails via any mail server other than themselves in attempt to stem the tide of spam. The blocking is typically done for smtp server definitions that use port 25 which is the default sending mail port. The effect to you is then if you try to send your e-mail through our e-mail server (smtp.athabascau.ca) an error message will appear usually similar to "smtp.athabascau.ca - server unreachable or not answering - contact administrator". The Internet Service Provider is being a good Internet citizen and blocking the attempt to send e-mail through any but their servers.
If you are getting the error above you will need to change the settings within your Mozilla/Thunderbird.
In Mozilla click on:
"Edit" - "Mail & Newsgroup Account Settings" - then "Outgoing Server (SMTP)"
Once the settings are in click "Ok" then try to send a new message. Sometimes you will not be able to send an existing draft or composition.
In Thunderbird click on:
"Tools" - "Account Settings" - "Outgoing Server (SMTP)"
You should see a screen very similar to this:
Highlight the smtp.athabascau.ca, then click on "Edit", you should now see similar to this:
Once the settings are in click "Ok" then "Ok" again , try to send a new message. Sometimes you will not be able to send an existing draft or composition.
Common SMTP server names.
Telus
smtp.telus.net
Shaw - Default setting - You may need to use one of the ones below if this does not work.
shawmail
Shaw - Edmonton
shawmail.ed.shawcable.net
Shaw - Calgary
shawmail.cg.shawcable.net
MCSNet
mail.mcsnet.ca
Interbaun
smtp.interbaun.com
If you use another internet provider you may need to contact them for their Outgoing server (SMTP) address.