I'm currently trying to add the feature of sending an e-mail from a custom object in LEX. However all the results I found were either related to sending a specific template or using hacks (which is not available in Lightning Experience).
Could anyone explain the best way to implement this in Lightning Experience?
EDIT* Changed LEX to Lightning Experience
Best Answer
This is possible without any hacks.
Steps:
Go to your page layout for your custom object.
Click on the wrench in the page layout labeled "Salesforce1 and Lightning Experience Actions." You will see multiple actions fill in.
In the above Screen grab, I had already added it, please proceed with next steps.
Go to the "Salesforce1 and Lightning Actions" pane.
Add the Send Email Action to the page actions.
PS. If you users would like to insert a template, change markup, add attachments or preview, they should use the icons next to the send button.