Postfix : SMTP; Client does not have permissions to send as this sender

If you are trying to send mails through Postfix using SMTP credentials and you are getting above error, here is the solution for you.

Check the 'from address' in the log file, this is not the same email address what's your login email id. To make the 'from address' same as login email id add following lines in the file /etc/postfix/main.cf
canonical_maps = regexp:/etc/postfix/canonical

canonical_classes = envelope_sender
canonical_maps = regexp:/etc/postfix/canonical

Now create a file /etc/postfix/canonical and add your smtp login email address in the file

// username@domainname.com

(user both back slashes in the file)

Now it will send mails by this 'from address'.

Postfix : SASL authentication failed

SASL authentication failed; cannot authenticate to server smtp.server.net[52.75.xx.x]: generic failure

If you are trying to send mails through Postfix using SMTP credentials and you are getting above error, here is the solution for you.

You need to add the following line in the file /etc/postfix/main.cf

smtp_sasl_mechanism_filter = login

Restart postfix.

I am assuming, you have added following parameters in main.cf file already.

relayhost = [smtp.server.net]:587
smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtp_sasl_security_options =
smtp_tls_CAfile = /etc/postfix/cacert.pem
smtp_use_tls = yes

dynamodump error : u'message': u'The security token included in the request is invalid.

Solution :
You have not added access keys and secret keys in the file $HOME/.aws/credentials. Add the content in the file.

cat ~/.aws/credentials
[default]
aws_access_key_id = AKIAJSEXAMPLEHXI3BJQ
aws_secret_access_key = 5bEYu26084qExAmPlE/f2pz4gviSfoOgSaMpLe39