So we use GoDaddy cpanel hosting for our website & basic email.. (We're a small company and don't do a huge volume of email). We've noticed lately that our outbound emails are being flagged as "SPAM" by GMail etc.. Resulting in our clients missing emails from us.
I called GODaddy Support today, and instead of offering any sort of solution, the immediate answer was "you need to upgrade to something else" that costs an additional $600+ per year!
What a crock! Why not offer a SOLUTION instead of just scamming me out of more money?? Try FIXING your problems GoDaddy. I'm not going to pay you any more, after I've already paid you a huge amount of money for our Cpanel hosting for 5 years in ADVANCE!
I'm sorry to hear your email is getting flagged as spam - I am a GoDaddy end user like you.
There are a couple of reasons that Google may flag things as spam which includes (but not limited to)
Content, fonts & links in your email (See https://fulcrumtech.net/resources/avoiding-gmail-spam-filter/)
Without seeing the "headers" of the email that went to spam it is hard to say just do XYZ to fix it. It is also possible that one person with Google Mail accidentally flagged something as spam and until enough people then say it's not spam, the filter will grab it
Personally, I do not recommend using the cPanel servers for email - from a technical perspective, if your server ever has an issue (resources, tech issue, billing issue) not only is your website down but your email is down.
For my clients that need email hosting I recommend one the following
1) Google Suite (preferred choice)
2) Office 365 if they need / prefer to by Microsoft based
3) ZohoMail - They have a free version for 5 users / 25GB /user - but is webmail only
ZohoMail has a plan at $1/user/month
I find this is a much better option as it is moving your mail from where your website is are services specifically designed for mail, vs many different functions