You should check to see if the messages that are being sent contain any links that would be considered questionable/spammy. You can also try taking the content of one of the messages and checking it’s spam assassin score ( https://spamcheck.postmarkapp.com ). Source: over 2 years ago

Build a clean email that passes a spam check with flying colors (https://spamcheck.postmarkapp.com/) then use a warmup service like lemwarm, inboxally or neverspam as mentioned in the other comments. Source: almost 3 years ago

The issue sounds more email centric. You're likely hitting the Apache SpamAssassin limit on the remote email servers. Use https://spamcheck.postmarkapp.com/ to check the score of emails you've had declared spam, and follow recommendations to improve. Source: about 3 years ago

Ipstack - Locate and identify Website Visitors by IP Address. - Source: dev.to / 4 months ago

Looking to enhance your website or application with location-based services? Look no further! ipstack's Geo Lookup API is the perfect solution for seamless and accurate geolocation data retrieval. With this Free Geo IP API, you can easily obtain vital information about your users or customers, such as their country, city, latitude, longitude, time zone, and more. ipstack's API is renowned for its reliability and... Source: 10 months ago

Not really their fault. I think they mostly use https://ipstack.com/ for IP Geolocation API - their support is not the best when it comes to updating IP info. Source: 11 months ago

I had to contact https://ipstack.com/ / http://co.apilayer.net/ 5 or 6 times until they corrected the database, and Azure Sign-in logs started showing the correct details. Source: over 1 year ago

There's even a free API: https://ipstack.com/ Does seem to be less accurate than the source mylocation.org uses, as ipstack seems to think my ipv6 address is in Mons, while mylocation sees my ipv4 address as Leuven-area (which is correct). Source: over 1 year ago