Catch-alls are typically safe, but there is a chance they will bounce, since by nature they are catch-all emails. Sending only to valid is of course the safest, however, this may limit your list outreach a bit.
Different email validation tools may return different statuses because they use different algorithms and criteria to validate email addresses. Email validation tools use a variety of methods to determine whether an email address is valid or not, including syntax checks, domain checks, and SMTP checks.
For example, some email validation tools may only check the syntax of an email address to ensure that it is correctly formatted, while others may also check the domain to ensure that it is registered and active. Some tools may even attempt to verify that an email address exists by sending a test email and analyzing the SMTP response.
Additionally, email validation tools may use different databases or data sources to check email addresses, which can also affect the results. Some tools may have more comprehensive data sources that allow them to verify a wider range of email addresses, while others may be limited in the scope of their data.
Finally, it's important to note that email validation is not an exact science, and different tools may have different definitions of what constitutes a "valid" email address. For example, some tools may consider an email address to be valid if it is syntactically correct and the domain is registered, even if the email address does not actually exist. Other tools may require additional verification steps to consider an email address valid.
In summary, different email validation tools may return different statuses because they use different algorithms, criteria, and data sources to validate email addresses, and because there is no single, definitive definition of what constitutes a "valid" email address.
Long story short, and as mentioned above, it's not a perfect science. It is up to you if you would like to include any certain status to be allowed to send to or not from within Uptics.
Click here to learn about the email validation tools available for use in Uptics.