@fruid I'd still test your mail with the mail-tester tool mentioned above to make sure your email doesn't appear "spammy". Depending on your settings and whether you're sending through the mail server of your hosting your mail may appear to be unauthenticated. Anyway, it's curious that WireMailSmtp isn't working but WireMailPHPMailer is, are you using the same settings for both?
By the way, I'd be slightly wary when the provider tells you to use port 587. In general, TLS-encrypted mail should use port 465. Port 587 is for STARTTLS, which starts SSL-encryption only after a connection has been established, which means you're susceptible to a man-in-the-middle attack. Your hoster only supports port 25 (plain text) and 587 (STARTTLS), that's a red flag.
Anyway, if you're using the suggested settings for SMTP connections by your hoster and they're not working, I'd just talk to them to see what might be the problem.