(I use one of the providers not recommended “due to cost”)
PostScan Mail - claims it started in 2012: https://www.postscanmail.com/about.html , which corroborates with their Android app https://play.google.com/store/apps/details?id=com.postscanma... and Internet Archive https://web.archive.org/web/20250000000000*/https://www.post...
Escapees - claim to be the oldest, having started in '85. But their Android app was released in 2018: https://play.google.com/store/apps/details?id=com.companynam..., the iOS app owner is different brand and the copyright on that listing says the company started in '95: https://apps.apple.com/us/app/escapees-mail-service/id161252.... Domain was only bought less than 2 years ago: https://whois.domaintools.com/escapeesmailservice.com
So, should you choose Escapees based on what they claim on their site?
As an aside, I used to analyze insurance companies' creditworthiness, and saw how they played the branding game because people cared about longevity.
I find their envelope and content scan quotas to be very reasonable, and have never exceeded them; they process all of my personal/family/business mail. They were also friendly when I inquired about writing code to wrap around their website UX to automate certain workflows.
https://www.sbimailservice.com/mail-scan-pro/
(no affiliation besides being a customer, I am just an internet rando)
Thanks for the convo btw! Got me reminiscing about my days in insurance.