block address lookup?
Printed From: LogSat Software
Category: Spam Filter ISP
Forum Name: Spam Filter ISP Support
Forum Description: General support for Spam Filter ISP
URL: https://www.logsat.com/spamfilter/forums/forum_posts.asp?TID=6513
Printed Date: 14 March 2025 at 7:32pm
Topic: block address lookup?
Posted By: dcook
Subject: block address lookup?
Date Posted: 27 June 2008 at 12:31pm
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Are there any settings to block address verification? Many spam tools try to verify email addresses by starting a send to an email then dropping the connection after verification by a "250 ok" message. How can we avoid this verification?
DC
------------- Dwight www.vividmix.com |
Replies:
Posted By: LogSat
Date Posted: 27 June 2008 at 6:12pm
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SpamFilter will always send a 250 confirmation, regardless of what the recipient email address is (as long as the sender's IP does not match one of the IP-based filters, and that filter is configured for "do not quarantine").
If you implement the "Authorized Emails TO" whitelist, which specifies the list of valid email addresses on your mail server, then SpamFilter will only send the 250 OK message in response to valid addresses, but will drop the connection in case of invalid addresses (in some cases SpamFilter will reject the RCPT TO address without disconnecting the sender, I can provide more on this if you're interested). Stopping the entire email verification process as a whole is pretty hard, since the process does start out like a regular email but then the sender never follows thru.. ------------- Roberto Franceschetti http://www.logsat.com" rel="nofollow - LogSat Software http://www.logsat.com/sfi-spam-filter.asp" rel="nofollow - Spam Filter ISP |
Posted By: dcook
Date Posted: 27 June 2008 at 6:28pm
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Thanks for the quick reply. Many ISP's are now refusing email address verification. If we had this feature would it not help with harvested or sold email addresses as a spammer would probally verify email addresses before sending and bouncing a bucket load?
Just a suggestion. Thanks.
 D ------------- Dwight www.vividmix.com |
Posted By: dcook
Date Posted: 01 July 2008 at 10:34am
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What situations create this ... "in some cases SpamFilter will reject the RCPT TO address without disconnecting the sender, I can provide more on this if you're interested?"
D ------------- Dwight www.vividmix.com |
Posted By: LogSat
Date Posted: 01 July 2008 at 4:14pm
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If the Bayesian filter is enabled in SpamFilter, *and* the option to "Receive full emails if recipient not in Authorized TO whitelist" is checked (this setting is located on the Bayesian filter tab), then in this case SpamFilter will reject the RCPT TO address without disconnecting the sender.
Furthermore, the following option is available in the SpamFilter.ini file as of SpamFilter v3.5.4.702: ;If the "AuthorizedTO" whitelist is used to specify the list of valid email addresses that can be accepted, by default SpamFilter will terminate a connection when the remote server specifies an invalid address in the RCPT TO command. You can use the following option to disable this forced disconnect, and cause SpamFilter to simply reject the invalid recipient, and continue to accept additional ones DisconnectOnNonAuthorizedTO=false ------------- Roberto Franceschetti http://www.logsat.com" rel="nofollow - LogSat Software http://www.logsat.com/sfi-spam-filter.asp" rel="nofollow - Spam Filter ISP |