@Jonnyd what phone do you have??
you phone could be affected by this announcement if it is older than 2017
https://productioncommunity.publicmobile.ca/t5/Announcements/Picture-and-Group-Messaging-End-Date-Fe...
,but you can first try this
click Reset All networks or Reset network settings to get the latest APN
Also, you can make a manual update, here are the old and new settings
Old settings:
APN: sp.mb.com
MMSC: http://aliasredirect.net/proxy/mb/mmsc
MMSC proxy: 74.49.0.18
MMS port: 80
MCC: 302
MNC: 220
APN Type: default,supl,mms
or default,mms,agps,supl,fota,hipri
New Settings:
APN: sp.mb.com
MMSC: http://aliasredirect.net/proxy/mb/mmsc
MMSC proxy: mmscproxy.mobility.ca
MMS port: 8799
MCC: 302
MNC: 220
APN Type: default,supl,mms
or default,mms,agps,supl,fota,hipri
