Sending Email

Send email message

Free Pascal users have some options when sending email. Some library such as Indy has TIdSMTP which connect directly to SMTP server. As alternative, Fano Framework offers a way to send email by using sendmail binary.

IMailer interface

To abstract away mail sender implementation, IMailer interface is provided. It is a contract for any class having capability to send email.

Sending email with sendmail

Current implementation of IMailer interface supports sending email using sendmail binary, from ssmtp library thorough class TSendmailMailer. To use it, register its factory class with container.

container.add('mailer', TSendmailMailerFactory.create());

var amailer : IMailer;
...
amailer := container['mailer'] as IMailer;
amailer.recipient := 'recipient@example.com';
amailer.sender := 'no-reply@example.com';
amailer.subject := 'Hello';
amailer.body := 'Hello world';
amailer.send();

Setting up ssmtp library

To install ssmtp in Debian-based distribution,

$ sudo apt install ssmtp

or Fedora-based,

$ sudo yum install ssmtp

Edit /etc/ssmtp/ssmtp.conf and add following lines,

mailhub=smtp.yourownserver.com:25
AuthUser=YourUsername
AuthPass=YourOwnSecretPassword
FromLineOverride=YES

Replace mailhub, AuthUser, AuthPass with your own value. If you do not setup dedicated SMTP server, you can use external SMTP server such as gmail or mailtrap, or MailHog. Both mailtrap and MailHog is fake SMTP server which helps sending test email without fear of becoming email spammer during development.

For example, this is configuration for sending email with mailtrap.io on development machine. You should replace YourUsername and YourOwnSecretPassword with username and password of your mailtrap.io account.

mailhub=smtp.mailtrap.io:2525
AuthUser=YourUsername
AuthPass=YourOwnSecretPassword
FromLineOverride=YES

Mailtrap.io credential

To test if your configuration works, try to send an email from command line

$ echo -e 'Subject: test\n\nTesting ssmtp' | sendmail -v tousername@example.com

Sending email with Indy

Current implementation of IMailer interface supports sending email using Indy, thorough class TIndyMailer. To use it, register its factory class with container.

container.add('mailer', TIndyMailerFactory.create());

var amailer : IMailer;
...
amailer := container['mailer'] as IMailer;
...

To be able to use TIndyMailer you need to add conditional compilation define USE_INDY in your project.

{$DEFINE USE_INDY}

or add it via Free Pascal configuration file or commmand line.

-dUSE_INDY

When using Indy, you need to be aware of intentional memory leak issue of Indy library.

You need to set INDY_DIR environment variable to point to Indy library base directory.

$ export INDY_DIR="/path/to/Indy"

Sending email with Synapse

Current implementation of IMailer interface supports sending email using Synapse, thorough class TSynapseMailer. To use it, register its factory class with container.

container.add('mailer', TSynapseMailerFactory.create());

When you need its instance, query it from service container.

var amailer : IMailer;
...
amailer := container['mailer'] as IMailer;
...

To be able to use TSynapseMailer you need to add conditional compilation define USE_SYNAPSE in your project.

{$DEFINE USE_SYNAPSE}

or add it via Free Pascal configuration file or commmand line.

-dUSE_SYNAPSE

And set SYNAPSE_DIR environment variable to point to Synapse library base directory.

$ export SYNAPSE_DIR="/path/to/synapse"

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