A Sprint spokesperson said it resulted from a "maintenance update" for messaging platforms at multiple US carriers and would not explain further.
Several people shared similar text message exchanges on Twitter.
Nearly 200,000 Americans woke up on Thursday to Valentine's Day text messages that had been delayed by months because of a network glitch.
A telecom vendor called Syniverse said a server failed on February 14, and almost 170,000 messages from multiple carriers didn't go through.
That's the nightmare some people woke up to this week in the United States after a cellphone server issue left almost 170,000 messages from Valentine's Day hanging in cyberspace until now. They claim that the issue has been resolved but wants to review its internal processes to ensure it won't happen again.
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"We apologize to anyone who was impacted by this occurrence", said William Hurley, Chief Marketing and Product Officer, Syniverse. "The last few months haven't been easy and just when I thought I was getting some type of closure this just ripped open a new hole".
"We're aware of this and it is resolved", a spokesperson mentioned.
"Now it's amusing", she said. Her sister and her sister's husband did not answer.
"On Feb. 14, 2019, a server failed, and messages were in queue at the time", telecom vendor Syniverse said in a statement on Thursday. "I believe we should have a reasonable right to privacy, but of course someone is looking at everything, you got to be careful, you have to take care of yourself", he says.
Many who were affected by the error say they are now anxious about the safety and security of their text messages.
Verizon referred CNN Business to Syniverse, which confirmed the incident.
Initially, Syniverse said "168,149 previously undelivered text messages were inadvertently sent to multiple mobile operators' subscribers", citing "an internal maintenance cycle" as the cause.
AT&T, CNN's parent company, did not respond to a request for comment by the network.