Incorrect authentication data

First off I just want to say thank you Yehudah!
This plugin has helped me with so many of my clients and I couldn’t recommend you enough.

I don’t need a solution or anything just wanted to let you know what was going on.

The Issue
I just wanted to flag something to you because I honestly have no idea what is happening. I installed the Post SMTP plugin just as I do with my other sites and followed through with the Wizard to ensure that all the credentials were correct but I keep getting an “Incorrect authentication data”.

Actions I Took
So I went through the error page to see what was going on:
https://postmansmtp.com/incorrect-authentication-data/

• I tried adding the TXT records to my DNS [I’m using site ground]
• v=spf1 ip4:I_DUNNO_IF_I_CAN_SHOW_THIS include:spf.protection.outlook.com -all

This didn’t work so I went through the rest to see what else could help. You mention restricting SMTP to root, but I couldn’t find that option on SiteGround. What I did find was the mention of an SPF validation protocol so I tried adding that to the DNS records too.

• v=spf1 +a +mx +ip4:DIFF_IP_ADDY include:_spf.mailspamprotection.com ~all

That also didn’t work.

Then I thought it may be because I jumped around to so many different hosting platforms or something but I can’t seem to get your plugin to work with my personal site only. So I cleared up all my DNS records and tried redoing them all again but it still doesn’t seem to work.

I wish I copied the errors so I could show it to you but I forgot to do that still. Anyways I started disabling a bunch of plugins to see if there’s was a conflict… Nothing. Lastly, I tried an alternative: WP Mail SMTP by WPForms and for some reason this one works.

The page I need help with: [log in to see the link]