On 2025/06/26 10:33, Support 3Hound via mailop wrote: > Dear list, > is it fair/correct to check the existence of a mailbox for about 30/50 mail > addresses/day? > They quite always will be present unless misspelled or typo that may be a > couple in a month. > We must RSET and then QUIT every the smtp connection just after the RCPT TO > answer because we > must check the data but we cannot contact these users.
I think you may find yourself getting blocked by some mail servers if you make frequent address-testing attempts without delivering mail. Also, testing an address with RCPT TO is not enough, you can still have a permanent failure after that point - either within the session when finally submitting the email (DATA / .) or later in a bounce (store-and-forward systems where the receiving MX doesn't have full knowledge of the valid user list). > Long explanation (preventing the double opt-in and bad-collecting process > objections): > Our customer collect e-mail addresses written over paper signed contracts > (they sell contracts > in behalf of an energetic company). > The process we manage for them is a sort of CRM that collect, sanitize and > send data to the > energetic company via API in different steps (required in their technical > flow). > We (and the customer) cannot send any e-mail to the end user due to the > agreement (sell > mandate). Our customer act in behalf of the energetic company, also the > privacy consent don't > give him the right to send any e-mail to the final user. Only the energetic > company that is the > data owner can contact them, we (and our customer) act as "external data > processor" we only act To my eyes, the main difference between your testing addresses with RCPT TO, and actually sending an email, is that the recipient doesn't know that you did it (unless they run their own mail infrastructure and check logs). Seems like no difference from a data privacy perspective. Some people might see "testing with rcpt to" as contacting them. > what the data owner request us and they request not to contact the customer > after the contract > is signed. > If a wrong address is inserted, our customer doesn't get paid for that > contract. If more than > 1 error is present in the same period, he risks also to loose the sell > mandate because that > e-mail address is also used to recognize and de-duplicate customer (both with > phone number and > physical address), so it may became a serious duplication issue to manage for > the energetic > company and a serious damage for our customer not to check the existence of > the address. This sounds like a bad arrangement for your customer. _______________________________________________ mailop mailing list mailop@mailop.org https://list.mailop.org/listinfo/mailop
