WP mail SMTP does not send e-mails

Form Question

I have a problem with JetFormBuilder forms, from Crocoblock.

I have configured a form adding the actions of verifying mail and user registration, to use it as the “Registration Form” of my website.

In this, when a user enters their details, they are automatically registered as a user with the default WordPress role/profile, “Subscriber”. However, the form actions are configured so that when the user verifies the email (i.e. when they open the link that should arrive to their email address) the account is verified and transformed to a “Customer” role.

The problem comes when receiving the emails.

Specifically, we have installed the “WP Mail SMTP” and “WP Mail Logging” plugins, in order to link our mail with the WordPress site and that all mailings are sent from the address “[email protected]”. These addresses (our personal emails) are hosted on the “Dinahosting” server.

So, we have found that there are some email addresses on which we do not receive these “verification emails”. For example, the verification emails are received correctly in the email of [email protected] (Google does not give problems), but they are NOT received in [email protected] or [email protected]. Likewise, we know that it is not these specific domains since, for example, the emails are received correctly at other addresses with the same hosting such as [email protected] or [email protected]. In short, it is some specific addresses that cannot receive emails.

So… my steps and what I have taken into account so far:

When I proceeded to install these plugins (WP Mail SMT and WP Mail Logging), I saw that I should have also installed another one called “WP Staging Pro”, but I didn’t install it because I saw that it was only for backups. I don’t know if this could have anything to do with it or would it really be necessary to install it?

As we have talked to Crocoblock support, we know that the JetFormBuilder plugin is taking (in the configuration of the function.php file of my WordPress site) the mail assigned and configured by “WP Mail SMTP”. CHECKED.

As for the SMTP mail server, we have verified that everything is correct (it has been tested by Dinahosting’s own support), so the problem does not lie here. We have checked that no outgoing mail is received through port 465 with SSL encryption (which we have added in the DNS of our WordPress site; specifically, we have added the SPF and DKIM). In addition, we also checked the DNS propagation, in case there were any problems with SPF and DKIM, but found no apparent errors.


We have also checked the mail addresses using the test emails of the “WP Mail SMTP” plugin, to make sure that the mentioned emails (the ones that give the error when not receiving the verification email using the form) are not failing on their side. In this case, the “test mail” arrives perfectly, without errors, so we know that it is not the configuration of the plugin “WP Mail SMTP”. The domain check results (the SPF) are correct.


On the other hand, in the “WP Mail Logging” plugin you can see the sending traffic, but it also has another section where it shows the route that follows the IP packets from the source to the destination and, in this one, you can see directly that it has NO response from the IP address.

So, if I’m not mistaken (from what I’ve seen), the problem is neither with the JetFormBuilder plugin, nor with the Dinahosting server.

We believe that the root of the problem is on the mail gateway, WP Mail SMTP, since it is not detecting the user’s IP, so it does not send the verification email.

Do you think the error could be due to this? If so… how can I fix it?If not… what do you think could be causing this failure?

On the other hand, regarding the “WP Mail SMTP” plugin, is it recommended that we have the DMARK configured?

PS: do you have a personal email to talk to technical support or a way to provide private support?

• This topic was modified 2 years, 6 months ago by GreenGreyGroup.