Here are the settings:
SaskTel 3G+ (Name)
APN: inet.stm.sk.ca
MCC:302
MNC:780
APN type: default
After creating this setting – save the apn
Now, create a new apn setting
Sasktel mms (name)
APN: proxy.stm.sk.ca
Proxy: mig.sasktel.com
Port:80
MMSC:
http://mms.sasktel.com
MMS Proxy: mig.sasktel.com
MMS Port: 80
MCC: 302
MNC: 780
APN Type: mms
After creating this setting save the file
Now, the first apn must be selected.