I am unable to receive MMS Messages on my iPhone

i started using a smart phone about seven years ago. two 5s and currently an se 2nd edition. i have always left my data off during the day. in addition , i never turn on imessage. every evening i turn the data on to check for mms messages. this has worked flawlessly for me during that period. about two weeks ago, however, this tactic began to fail. i'm not receiving mms messages that i know have been sent. i had verizon install a new sim card yesterday but the problem still exists. could i have turned something off or on in the phone that sabotaged my little gig. i thank you for your advice

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