MailyGo

MailyGo is a small tool written in Go that allows to send HTML forms, for example from static websites without a dynamic backend, via email. It can be used for contact forms on pages created with Hugo (example).

MailyGo is lean and resource-saving. It can be installed with just one executable file.

Installation

MailyGo can be compiled with the following command:

go get -u codeberg.org/jlelse/mailygo

It can then be executed directly.

Configuration

To run the server, you must set a few environment variables from the list below.

Name	Type	Default value	Usage
SMTP_USER	required	-	The SMTP user
SMTP_PASS	required	-	The SMTP password
SMTP_HOST	required	-	The SMTP host
SMTP_PORT	optional	587	The SMTP port
EMAIL_FROM	required	-	The sender mail address
EMAIL_TO	required	-	Default recipient
ALLOWED_TO	required	-	All allowed recipients (separated by ,)
PORT	optional	8080	The port on which the server should listen
HONEYPOTS	optional	_t_email	Honeypot form fields (separated by ,)
GOOGLE_API_KEY	optional	-	Google API Key for the Google Safe Browsing API
BLACKLIST	optional	gambling,casino	List of spam words

Special form fields

You can find a sample form in the form.html file. Only fields whose name do not start with an underscore (_) will be sent by email. Fields with an underscore serve as control fields for special purposes:

Name	Type	Default value	Usage
_to	optional	-	Recipient, it must be in ALLOWED_TO, hidden
_replyTo	optional	-	Email address which should be configured as replyTo, (most probably not hidden)
_redirectTo	optional	-	URL to redirect to, hidden
_formName	optional	-	Name of the form, hidden
_t_email	optional	-	(Default) "Honeypot" field, not hidden, advised (see notice below)

Spam protection

MailyGo offers the option to use a Honeypot field, which is basically another input, but it's hidden to the user with either a CSS rule or some JavaScript. It is very likely, that your public form will get the attention of some bots some day and then the spam starts. But bots try to fill every possible input field and will also fill the honeypot field. MailyGo won't send mails of form submissions where a honeypot field is filled. So you should definitely use it.

If a Google Safe Browsing API key is set, submitted URLs will also get checked for threats.

License

MailyGo is licensed under the MIT license, so you can do basically everything with it, but nevertheless, please contribute your improvements to make MailyGo better for everyone. See the LICENSE file.