I have a WordPress site hosted on a shared cPanel Linux server at GoDaddy. cPanel emails are used to send confirmation notices to users after an event or transaction (e.g., registration or purchase). cPanel email is also used when cron jobs trigger notices.
I am having deliverability issues with cPanel emails. Outlook.com (Hotmail) blocks GoDaddy cPanel emails. Gmail delivers cPanel emails to the spam folder.
GoDaddy recommends switching to virtual private server hosting to improve email deliverability.
I presume I could also use a transactional email service provider to send notices when an event, transaction, or cron job triggers them.
1. Which of the two options is more potent in improving email deliverability? … switch hosting to virtual private server or use transactional email service provider.
2. Would using both of the options bring added benefits or just be overkill?
You could fix your email issues using Transaction ESP, like SendGrid.
Install this plugin in WordPress https://wordpress.org/plugins/wp-mail-smtp/
Which switches all emails to use SMTP and you set it up with your ESP's SMTP credentials.
I do this a lot with sites on cloud instances and it works very well.
On top of that, using an ESP like SendGrid you can actually see statistics of who is getting the email, bouncing, opening, etc... Great stuff, especially for a online business.
Going through your question and detail I could see you are having this same issue now which I faced few years ago with my WordPress setup.
For information all shared hosting provider use default linux SMTP to send outgoing emails which use sendmail to deliver emails and most of the time they miss-out important sending domain configuration like SPF, DKIM, DMARC records. And impact email delivery.
Don't worry about this as these can be easily fixed with following setup.
In order to fix this, you should use SMTP relay like ( ESP ) to deliver email externally, but here you should configure following important records on your email sending domain name:
SPF record according to your SMTP relay provider
DKIM record according to your SMTP relay provider
DMARC according to your sending domain name
Apart from above also configure your email sending domain name to your Google Postmasters account ( This is like Google webmasters for emails ).
This technology setup improved my email to all subscribers and my email open rate boosted from mere 17% to 48%.
Coming to SMTP email service provider, looking at your requirement, I would recommend to use SendGrid or SparkPost. SparkPost is quite easy to configure.
After above have been properly configured and aligned with your domain name, you should install https://wordpress.org/plugins/wp-mail-smtp/ wordpress plugin and add your SendGrid / SparkPost configurations.
I know these may sound little tricky for you. Let me know I can help you with complete setup within few minutes.
Wish you the best for your success!