Category: Mail – Page 2

Install SSL Certificate on Zimbra mail server

Posted on August 9, 2019 by ServerOk

To install SSL certificate for Zimbra Mail Server, login to server, switch to user zimbra

su - zimbra

1	su - zimbra

Now create file commercial.key, paste your Private key.

vi /opt/zimbra/ssl/zimbra/commercial/commercial.key

1	vi /opt/zimbra/ssl/zimbra/commercial/commercial.key

In commercial.crt, paste your SSL certificate.

vi /opt/zimbra/ssl/zimbra/commercial/commercial.crt

1	vi /opt/zimbra/ssl/zimbra/commercial/commercial.crt

Create commercial_ca.crt with content of your ca-bundle file.

vi /opt/zimbra/ssl/zimbra/commercial/commercial_ca.crt

1	vi /opt/zimbra/ssl/zimbra/commercial/commercial_ca.crt

Verify SSL cerificate

/opt/zimbra/bin/zmcertmgr verifycrt comm /opt/zimbra/ssl/zimbra/commercial/commercial.key  /opt/zimbra/ssl/zimbra/commercial/commercial.crt

1	/opt/zimbra/bin/zmcertmgr verifycrt comm /opt/zimbra/ssl/zimbra/commercial/commercial.key /opt/zimbra/ssl/zimbra/commercial/commercial.crt

If SSL verified sucessfully, you can install it with command […]

Email Marketing

Posted on July 21, 2019 (September 28, 2019) by ServerOk

https://www.gmass.co – Allow you to send mass email using Gmail and G Suite. OpenEMM – Install instructions. […]

DMARC

Posted on July 11, 2019 by ServerOk

DMARC is used to protect your email from email spoofing. DMARC use SPF and DKIM record to validate your email. DMARC is a TXT record added in your domain DNS. DMARC record look like

v=DMARC1;p=POLICY_HERE;pct=100;rua=mailto:postmaster@your-domain.com;ruf=mailto:admin@your-domain.com;rf=afrf

1	v=DMARC1;p=POLICY_HERE;pct=100;rua=mailto:postmaster@your-domain.com;ruf=mailto:admin@your-domain.com;rf=afrf

p=POLICY_HERE This specifies what to do with incoming email that fails DMARC. Valid options are none, quarantine and reject. p=none […]

Configure postfix to relay mails using Gmail

Posted on May 31, 2019 (August 10, 2020) by ServerOk

Install postfix

apt update
apt install postfix libsasl2-modules

1 2	apt update apt install postfix libsasl2-modules

Create file

touch /etc/postfix/sasl_passwd
chmod 600 /etc/postfix/sasl_passwd
vi /etc/postfix/sasl_passwd

touch /etc/postfix/sasl_passwd

chmod 600 /etc/postfix/sasl_passwd

vi /etc/postfix/sasl_passwd

Add

[smtp.gmail.com]:587    user@gmail.com:password

1	[smtp.gmail.com]:587 user@gmail.com:password

Save and exit editor. Run

postmap /etc/postfix/sasl_passwd

1	postmap /etc/postfix/sasl_passwd

Edit postfix configuration file

vi /etc/postfix/main.cf

1	vi /etc/postfix/main.cf

Find and remove

relayhost =

1	relayhost =

At end of the file, add

relayhost = [smtp.gmail.com]:587
smtp_use_tls = yes
smtp_sasl_auth_enable = yes
smtp_sasl_security_options =
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtp_tls_CAfile = /etc/ssl/certs/ca-certificates.crt

relayhost = [smtp.gmail.com]:587

smtp_use_tls = yes

smtp_sasl_auth_enable = yes

smtp_sasl_security_options =

smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd

smtp_tls_CAfile = /etc/ssl/certs/ca-certificates.crt

Restart postfix

systemctl restart postfix

1	systemctl restart postfix

Now all mails will be forwarded using gmail. Test Email Delivery Install mailutils

apt install mailutils

1	apt install mailutils

On CentOS

yum install mailx

1	yum install mailx

To sent test email, run […]

Zimbra Unable to validate certificate chain

Posted on March 19, 2019 (August 8, 2019) by ServerOk

On installing SSL on Zimbra mail server, i get following error

zimbra@zim:~/boby$ /opt/zimbra/bin/zmcertmgr verifycrt comm /opt/zimbra/ssl/zimbra/commercial/commercial.key  /opt/zimbra/boby/zim_simplecloud_co_za.crt
** Verifying '/opt/zimbra/boby/zim_simplecloud_co_za.crt' against '/opt/zimbra/ssl/zimbra/commercial/commercial.key'
Certificate '/opt/zimbra/boby/zim_simplecloud_co_za.crt' and private key '/opt/zimbra/ssl/zimbra/commercial/commercial.key' match.
** Verifying '/opt/zimbra/boby/zim_simplecloud_co_za.crt' against '/opt/zimbra/ssl/zimbra/commercial/commercial_ca.crt'
ERROR: Unable to validate certificate chain: /opt/zimbra/boby/zim_simplecloud_co_za.crt: C = US, ST = New Jersey, L = Jersey City, O = The USERTRUST Network, CN = USERTrust RSA Certification Authority
error 2 at 2 depth lookup:unable to get issuer certificate
zimbra@zim:~/boby$

zimbra@zim:~/boby$ /opt/zimbra/bin/zmcertmgr verifycrt comm /opt/zimbra/ssl/zimbra/commercial/commercial.key /opt/zimbra/boby/zim_simplecloud_co_za.crt

** Verifying '/opt/zimbra/boby/zim_simplecloud_co_za.crt' against '/opt/zimbra/ssl/zimbra/commercial/commercial.key'

Certificate '/opt/zimbra/boby/zim_simplecloud_co_za.crt' and private key '/opt/zimbra/ssl/zimbra/commercial/commercial.key' match.

** Verifying '/opt/zimbra/boby/zim_simplecloud_co_za.crt' against '/opt/zimbra/ssl/zimbra/commercial/commercial_ca.crt'

ERROR: Unable to validate certificate chain: /opt/zimbra/boby/zim_simplecloud_co_za.crt: C = US, ST = New Jersey, L = Jersey City, O = The USERTRUST Network, CN = USERTrust RSA Certification Authority

error 2 at 2 depth lookup:unable to get issuer certificate

zimbra@zim:~/boby$

This was due to SSL cert chain. The ca-bundle file they provided did not work with Zimbra. This is due to some issue with the order in witch CA Certificate files are placed. Here is zimba documentaion related to this issue https://wiki.zimbra.com/wiki/Fix_depth_lookup:unable_to_get_issuer_certificate I […]

Postfix Delete Mails from a user

Posted on February 16, 2019 by ServerOk

To delete emails from a particular user from postfix mail queue, run

postqueue -p | grep USER_HERE | cut -d' '  -f1 | postsuper -d -

1	postqueue -p \| grep USER_HERE \| cut -d' ' -f1 \| postsuper -d -

See postfix […]

imap

Posted on February 9, 2019 (October 28, 2020) by ServerOk

Migrate Emails using imapcopy https://i005.lamiral.info/X/ – Online imapsync […]

Migrate Emails using imapcopy

Posted on February 9, 2019 (November 17, 2020) by ServerOk

imapcopy is a program to copy mails from one IMAP mailbox to another. I was using this for email migrations. But for a large mailbox with 9300 mails, this failed. So i looked for alternatives. I installed imapsync, it was little annoying to install as it need lot of other packages installed for it to […]

PowerMTA

Posted on January 23, 2019 (April 18, 2020) by ServerOk

PowerMTA is highly configurable mail server for email marketing. Unlike general email servers, PowerMTA can be configured to meet your special mail delivery requirements. To reload PowerMTA

pmta reload

1	pmta reload

PowerMTA config file location

/etc/pmta/config

1	/etc/pmta/config

To see mail queue status, run

pmta show status

1	pmta show status

List mails in queue

pmta show queues

1	pmta show queues

[…]