@sticky2 -- the sender(s) were notified that you had a "mailbox full" or "mailbox over quota" condition.
Short answer: probably not. Shaw's mail-server "rejected" the message, rather than storing it. So, Shaw Support probably have no "archive" to scan for the "lost" messages.
See a previous thread on this forum: https://support.shaw.ca/t5/internet-discussions/didn-t-receive-any-emails-because-webmail-was-full-h...
which gives similar information.