Avoid vultr like the plague. A few years back, they tried to sneakily roll out a TOS change that claimed ownership over all hosted content. They did eventually roll it back reluctantly, but they initially resisted it and took pot shots at the community instead. It took a ton of consumer backlash to get them to fix it. Really slimy company.
But yes, generally VM providers are often also not SMTP providers / they block port 25. It’s pretty common to have your VM in one provider and get a cheap SMTP provider elsewhere as it’s a specialized skillset to get good e-mail deliverability. No need to move the VM.