Afzender van Exim verifi�ërt Callout of Callback kon niet voltooien of Controle Ontbroken Fout

Als u Webgastheer of e-mailserver gebruikend Exim of Sendmail als agent van de postoverdracht (MTA), in werking stelt en dat e-mail - of de postberichten die naar u, uw cliënten of gebruikers worden verzonden nu en dan verloren kunnen vond of nooit aan de brievenbussen aankwam, kan uw postserver slachtoffer aan vallen knoeit van afzendercontrole. Het is de most likely oorzaak van het missen van e-mail als u hebt geverifi�ërd dat e-mail niet door spamfilters of de controles van de troeppost vangt, en het domein van de postserver en IP het adres zijn niet onder enig (Zwarte Lijsten In real time) blok RBL.

Het symptoom van niet geleverde post of gestuiterde post kan ook in Exim of Sendmail foutenlogboek worden gecontroleerd en worden gezien. De post gewoonlijk wordt die door bestemmingsserver wordt verworpen (als de bestemmingsserver uw server is, wordt inkomende e-mail verloren, anders, uitgaande post wordt gestuiterd) met de volgende berichten:

550 de afzender verifi�ërt ontbroken

afzender 550 verifi�ërt verworpen exim

550 verifiëren geldigheid

verifi�ërt administratief verbod 550 „mailserver adres“

te verifiëren bericht 550 zijn zij geldig

550 de afzender verifi�ërt ontbroken - bevorder uw firewallingebouwde programmatuur of montages

550 verzonden niet - geen omgekeerde raadpleging

550 het systeem van de bestemmingspost verwierp uw terugkeeradres

550 de afzender moet bestaan

550 gevonden niet domein

De controle van de afzender is nieuwe maatregel proberen om e-mail spam besmetting tegen te houden en te blokkeren. De servers van de post of MTA zoals Exim die met populair controlepaneel zoals cPanel en WHM komt gebruikt nauwkeuriger een mechanisme genoemd afzender callouts of callbacks om volledige inkomend van te bevestigen: het adres van een verre afzender zoals die in de e-mailenvelop wordt gevonden is eigenlijk een echte lokale rekening op de verzendende postserver. Als de server van de oorsprongspost de valse waarde terugkeert, zal de inkomende post weigering zijn en niet door MTA van de voorgenomen ontvanger geweest.

Een gestuiterde e-mail zal aan de afzender en erop wijzen produceren gewoonlijk dat de controlepoging ontbreekt. Nochtans, aangezien de afzender niet echt bestaat, zodat zal niemand de post krijgen, en niemand weet wat aan de post gebeuren en waarom e-mail nooit werd geleverd. Aangezien niet elke postgastheer u door de postserver met normen volgzaam te maken RFC zou hinderen, zoals RFC 1123 die post van de ongeldige afzender, zodat goedkeuren wedt u het best om post ertoe te brengen veilig en veilig leveren bent ervoor te zorgen dat uw postserver bekwaam de post behoorlijk om te behandelen die van die onwetende partijen wordt verzonden.

So if you’re the sender who found that your mail mysteriously disappear for unknown reason, make sure you send mail out with a real and actual mailbox user account name. Using false or false mailbox name such as nobody@domain.com in hoping that nobody replies get back to you will likely to cause sender verification to fail, and no mail been routed and delivered.

If you keep receiving mails especially from mailing lists or subscriptions that using invalid sender address, and you can’t help but need to receive the email, the only choice is to instruct your MTA to accept these emails. There are basically two choices on how to do it, firstly by creating a white lists which unblock those known email addresses, and secondly, disable sender verification altogether to avoid any future issues. Second option is much easy way, but you run the risk of receiving more spam. Beside, the mail queue will also likely to grow larger or email will be rejected because the mail server will be accepting more faked spam messages. However, you don’t have to worry about lost emails and undelivered emails anymore due to sender using non-existent email address. Here’s a few tutorials on how you can achieve these tasks in popular web hosting control panel - cPanel/WHM.

How to Disable Sender Callouts Verification in cPanel/WHM 10.x

1. Login to the WebHost Manager.
2. On the Service Configuration section, click on Exim Configuration Editor link.
3. Uncheck and untick the checkbox next to Use callouts to verify the existence of email senders. option.
4. Press the Save button, and cPanel will auto restart Exim.

How to Disable Sender Callouts in cPanel/WHM v11

1. Login to the WebHost Manager.
2. On the Service Configuration section, click on Exim Configuration Editor link.
3. Uncheck and untick the checkbox next to ** Use callouts to verify the existence of email senders. Basiclly, exim will connect to the mail exchanger for a given address to make sure it exists before accepting mail from it. option.
4. Press the Save button at the bottom of the page, and cPanel will auto restart Exim.

Create Whitelist to Exclude from Exim Sender Verify Callbacks - Simple Whitelist Guide

If you don’t want to turn off sender callouts to verify the existence of email senders, you can also create a whitelist so that Exim will check against it to see if callout instruction for a particular sender can be ignored. Note that the steps need some basic knowledge on working with Unix shell, and involves manual modification of Exim configuration file, which any mistake will make the mail server not working.

1. Create a file that will record all trusted email addresses, i.e. /etc/whitelist_senders with each address on each line. Wildcard is accepted, such as *@domain.com will include all senders from domain.com.
2. In cPanel/WHM, click on Exim Configuration Editor under Service Configuration section. Then click on Advanced Editor button on the right pane.
3. In Advanced Editor top most text box, add the following code (if there is existing text, add below them):

   
addresslist whitelist_senders = wildlsearch;/etc/whitelist_senders


4. Scroll down to the next text box, where there should three text boxes together. This is the beginning of ACL section.
5. In the middle box of these three text boxes, search for the following 4 lines:

   
#sender verifications are required for all messages that are not sent to lists
require verify = sender/callout
accept domains = +local_domains
endpass


   Replace these 4 lines with the following code:

   
#sender verifications are required for all messages that are not sent to lists
deny
!verify = sender/callout
!senders = +whitelist_senders
accept domains = +local_domains
endpass


6. Scroll down the to the bottom end of the middle of the 3 boxes, locate these 4 lines:

   
#!!# ACL that is used after the DATA command
check_message:
require verify = header_sender
accept


   Replace these 4 lines with the following code:

   
#!!# ACL that is used after the DATA command
check_message:
deny
!verify = header_sender
!senders = +whitelist_senders
accept


7. Click on the Save button on the bottom of Advanced Editor.
8. Verify that Exim working properly by sending and receiving emails.
9. If Exim is not working properly, check the configuration file again for errors.
10. If Exim is working properly, add in the sender email address or domain that you’re having problem with to the white list file.
11. Ask the sender to send email to you again to verify the delivery.

Create Whitelist to Exclude from Exim Sender Verify Callbacks - Auto Exclusion with Whitelist Guide

There are some non-existent and invalid email addresses that always been used by administrators to send out emails, especially notifications and subscriptions. Such email always has the common words such as nobody, bounce, request, root, anonymous and etc. You can use this assumption to instruct Exim to automatically allow emails with these senders to go through to the recipients without sender verification. This reduce the works to add email addresses to white lists.

1. Create 3 files as below to act as your whitelists:

   
/usr/local/cpanel/base/eximacl/rv_callout_sender_domain_whitelist
/usr/local/cpanel/base/eximacl/rv_callout_receiver_domain_whitelist
/usr/local/cpanel/base/eximacl/rv_sender_verify_domain_whitelist


2. In cPanel/WHM, click on Exim Configuration Editor under Service Configuration section. Then click on Advanced Editor button on the right pane.
3. In Advanced Editor top most text box, add the following code (if there is existing text, add below them):

   
domainlist rv_callout_sender_domain_whitelist = lsearch;/usr/local/cpanel/base/eximacl/rv_callout_sender_domain_whitelist
domainlist rv_callout_receiver_domain_whitelist = lsearch;/usr/local/cpanel/base/eximacl/rv_callout_receiver_domain_whitelist
domainlist rv_sender_verify_domain_whitelist= lsearch;/usr/local/cpanel/base/eximacl/rv_sender_verify_domain_whitelist


4. Scroll down to the middle to locate the ACLs section, where 3 textboxes appear together (most likely top and bottom one are empty text fields). It should appears after begin acl.
5. In the middle box of the 3, locate the following line:

   
require verify = sender/callout


   Replace the above line with the following block of code:

   
# Deny unless the sender address can be verified.
deny message = From email address must be valid
# do not check address for lists or bounces
# or people in our company contact database
!senders = ^.*-request@.*:\
^bounce-.*@.*:\
^.*-bounce@.*:\
^owner-.*@.*:\
^listmaster@.*:\
^root@.*:\
^anonymous@.*:\
^nobody@.*
!domains = +rv_callout_receiver_domain_whitelist
!sender_domains = +rv_callout_sender_domain_whitelist
# do not check for DSN-ignorant domains
# those that don't accept MAIL FROM:<>
!dnslists = dsn.rfc-ignorant.org/$sender_address_domain
!verify = sender/callout=10s,defer_ok
##
# Check that there is a MX record for those that do not
# meet the deny statement requirements - ie bounces
# No cost as previous lookup is cached if executed
##
deny !sender_domains = +rv_sender_verify_domain_whitelist
!verify = sender


6. Click on the Save button on the bottom of Advanced Editor.
7. Verify that Exim working properly by sending and receiving emails.
8. If Exim is not working properly, check the configuration file again for errors.
9. If Exim is working properly, add in the sender email address or domain that you’re having problem with to the white list files.
10. Ask the sender to send email to you again to verify the delivery.

IMPORTANT: This is a machine translated page which is provided "as is" without warranty. Machine translation may be difficult to understand. Please refer to original English article whenever possible.

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