Alon wrote: > Hi All, > > I'm trying to understand what would be the impact of enabling: > > > # require_verify = sender > *snip*
There are long threads on pros, cons, etc. in recent archives here. Check those and the Exim 4.6X spec. > > How would this line affect the usage from my users: As ordinarily implemented, it should not affect MUA submissions at all. > 2. Users who use forms on the server and use localhost and do not use SMTP > full credentials,... Separate environment, and this is not the tool. You might want to look at 'check_local', but you will need *many* tools to keep webforms under control. > > 3. Users from Outside the server... 'Strangers' sending messages to your user community are the principle group affected. verify = sender tries to see if the 'incoming' mail server of-record for the domain they *apear* to come from both exists and accepts *at least* a partial attempt to send mail. Many malware sources will fail that. Further options in the spec. > > 4. Question number 3, .... dramatically less spam Yes, BUT - if used as 'require' you will almost certainly have loss of other mail as well. > > 5. If this is such a good feature, why would it be disabled... - Not all sender's servers can/do respond properly or promptly to the query. - Some very large / major ISP's do not have usable DNS records for their 'pools' of servers. - Many operators do not appreciate being hit with the query. - A few may even blacklist those who attempt such queries. Feature is perhaps at its best when used within a known-responsive environment - say one company's intranet or a 'pool' of MX or relay hosts. hosts / !hosts and hostlists or lookups can be used to specify which/which-not to apply it to if you choose to use it. Bill -- ## List details at http://www.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://www.exim.org/eximwiki/
