I've had a problem with emails I send for work (all to external domains) that are completely blocked or spammed, to many different recipients in various companies, since I changed my domain and hosting. I send 5-50 emails per day.
Previously it had a domain name "previous.co" with BlueHost. I changed to NameCheap 3 months ago and changed my domain name to "newdomain.io" at the same time (".com" was taken).
I have been sending emails to the same people as before, with similar messages.
Since I moved, I've had continuous issues with emails I send blocked (don't even appear in spam) or addressed to recipient spam. I have not had these problems before. They started immediately when I changed.
I have checked the shipping IP address and it is not blacklisted.
I asked recipients to whitelist my email address, with mixed results.. One company reported that they were whitelisted and that my emails to any email address for that company simply never appear. Another company was whitelisted and worked for them.
I also changed my email client in case that helped and made no difference. I was using MailSpring over IMAP, now I am using Postbox over IMAP. My sent emails appear in the sent send folder. I always send HTML and very often I have online images and attachments of all kinds.
I got a message from Microsoft stating that I was on an Outlook 365 block list, so that's a hint. I completed their form to request that the block be removed, I'm not sure if this was the case or not, but the recipient whitelisted my email and we were able to communicate for a week.
I am physically located outside of the US. USA, and almost all my recipients are in the USA. So I thought this might be a problem, but when I tracked the IP address in an email I sent, it only led to the Namecheap servers and there was no indication that I could see anywhere in my physical location .
I don't know what else to do except change my hosting from Namecheap to BlueHost; Or could the problem somehow be that my domain is too new or that it is a .io domain? Any suggestion?
Sorry for the lack of specific details, some of the tech stuff is on my mind a bit, but I'm happy to provide details if you know what to ask for.