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

PDF Compression Error

FPDF error: This document (testcopy.pdf) probably uses a compression technique which is not supported by the free parser shipped with FPDI

Solution : 
Download the file from here according to your operating system.
Mine is Linux x86 (64 bit) so I have downloaded Ghostscript 9.27 for Linux x86 (64 bit)
I renamed the file as gslin64. Original filename was gs-927-linux-x86_64.
Save it in /usr/bin.
Now run the following command

gslin64 -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dNOPAUSE -dQUIET -dBATCH -sOutputFile=/tmp/abc.pdf  input.pdf

where input.pdf is error pdf file and abc.pdf is error free output file which is saved inside /tmp directory