Overview cURL errors often indicate that your server’s cURL library is outdated or incompatible with your SMTP plugin. These errors are typically server-related rather than issues with the SMTP plugin itself. Causes There are two main reasons why cURL errors occur: Outdated cURL library: Your server’s cURL library may be outdated, leading to compatibility issues. […]
cURL Error 28: Connection Timed Out
Overview The cURL error 28 indicates a timeout occurred when your site attempted to make an HTTP request to the server. This error often happens if your server fails to respond to your chosen mailer’s request in a timely manner. Causes There are several reasons why cURL error 28 might occur: Server-related issues: Your server’s […]
SMTP Error: Key Not Found
Overview The ‘Key Not Found’ error usually means that a required configuration key, such as an API key, is missing or incorrectly set in your SMTP plugin. This can prevent emails from being sent successfully through your site. Causes Most email service providers (like SendLayer and Brevo) require an API key or authentication token for […]
SMTP Error: MailboxNotEnabledForRESTAPI
Overview The “MailboxNotEnabledForRESTAPI” error occurs when a mailbox isn’t enabled to use the REST API (used by applications to access mail, send emails, and other services in Exchange Online or Office 365). This can happen for several reasons, often relating to the type of mailbox or its settings. Causes This error often occurs when using […]
Error 553 Sender Address Rejected: Invalid Sender Email Address
Overview The “553 Sender Address Rejected: Invalid sender email address” error occurs when an email server rejects the sender’s email address. This can happen when you try to send an email from an address that the SMTP server does not recognize. Causes This error is often related to the Sender’s email domain, which is configured […]
SMTP Error 550 Host Unknown: Incorrect DNS Settings
Overview The “550 Host Unknown” error typically occurs when trying to send an email, but the mail server cannot deliver it because it can’t identify the recipient’s mail server. In simpler terms, the sending server doesn’t know where to deliver the email. This is most often a DNS-related issue, meaning that the Domain Name System […]