Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!feeder.erje.net!eu.feeder.erje.net!news.swapon.de!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail From: Arno Welzel Newsgroups: comp.os.linux.misc,comp.lang.php Subject: Re: testing email deliverability... Date: Fri, 06 Jun 2014 14:11:41 +0200 Lines: 28 Message-ID: <5391AFFD.8050809@arnowelzel.de> References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Trace: individual.net khUNqCr5g6d1I3tdi4K1vgOfxKIz9wZHRMP0sHR/yqrs4C0soh Cancel-Lock: sha1:XBIpeDRH0EZWuecAwnGF9Nz9daA= User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.5.0 In-Reply-To: Xref: csiph.com comp.os.linux.misc:11194 comp.lang.php:13801 Am 2014-06-05 02:48, schrieb The Natural Philosopher: > I have web contact pages which are used by anyone to send enquiries. > > I want to make sure that anyone using them has a valid reply address set > in a web form BEFORE I forward the message on to the site administrators. Without asking the MX you will never know, if the MX is willing to accept the mail. And even then - temporary 4xx-failures due to Greylisting are a valid behaviour as well as failures due to a quota limitation etc. - which all does *not* mean that the e-mail address is invalid. Unfortunately the opposite behaviour - accepting a RCPT TO without any error in return - must not be interpreted as "this is a valid address". Therefore the usual way to handle this is to send an e-email with a confirmation request so the user can approve that himself - combined with a database table to store the pending approvals (which should timeout after a certain time if no one approves the request - e.g. after 7 days). -- Arno Welzel http://arnowelzel.de http://de-rec-fahrrad.de http://fahrradzukunft.de