How to retrieve your MMS pictures?
You have two options:

As a member, you can directly provide your mobile phone number and password. You’ll be brought to your MMS space upon successful login at mmsweb.mts.net.
For unregistered user, you may receive your message key on your mobile phone. Please go to mmsweb.mts.net and login with your mobile phone [...]

Did you receive an SMS from Telus like this:
This is an MMS message. Please go to http://mms.telusmobility.com/do/LegacyLogin to view the message.
And when you try to access http://mms.telusmobility.com or http://mms.telusmobility.com/do/LegacyLogin, you get the error message like this:
Preferences
An internal error has occurred. The operation could not be completed.
Click here to return to the application.
Certainly, this is something [...]

Failed to send/receive MMS? Still looking to activate your MMS setting on your mobile phone?
Refer to the below configuration:
Rogers MMS Settings
APN: media.com
Username: media
Password: mda01
Gateway IP: 172.25.0.107
Message Server: http://mms.gprs.rogers.com
Quoted from Wikipedia:
Rogers Wireless, formerly known as Rogers AT&T Wireless, is a wholly owned subsidiary of Rogers Communications. Rogers purchased Fido in November 2004, creating Canada’s largest wireless [...]

Telus Mobility MMS login page will be at http://mms.telusmobility.com. It was accessible previously, but now the site seems down.
It gave an error of:

An internal error has occurred. The operation could not be completed.

If you encounter a similar problem, please post it here.

Quoted from Wikipedia:

Telus is a national telecommunications company in Canada that provides a [...]

How to send/receive MMS using Fido network?
Setting up MMS Application:
Service: Fido MMS (call it what ever you like)
Connection: GPRS
User name: fido
Password: fido
APN: internet.fido.ca
MMS Gateway Address: 205.151.11.13
MMSC URL: mms.fido.ca
MMSC Port Number: 9201
To save calls on Fido network, follow the settings:
APN: mms.fido.ca
IP: 205.151.011.013
Port:9201
Username: (leave blank)
Password: (leave blank)
MMS relay server http://www.fido.ca
Are you using iPhone, and having problem with [...]