I'm evaluating mailtrap for our outbound email testing needs. It seems like mailtrap accepts all email you send via SMTP. However in order to thoroughly test real-world scenarios, there should be a way to configure that, say, 1% of all mail will be soft-bounced, and 0.1% of all mail will be hard-bounced. Of course those number should be configurable, and even better if the user could configure specific SMTP result codes and enhanced status codes and control the percentages of each one.

Web Notifications.
So that when you receive a new mail, you get a nice popup :)

There doesn't seem to be an obvious way to create a bunch of users for an entire company group - this would make inbox addministration muc easier

It would be great if there was a way to look up messages using the message_id header via both the API and the web interface.

That way it would be easy to programatically verify that a give message was delivered using the API

Keyboard shortcuts

Allow users to sign up and access a shared inbox in one step.

Right now, users have to sign up, and then the inbox owner has to share the inbox with them in a separate step.

offer clients for different programming languages. my preference nodejs

Some hosts, such as GoDaddy, block all SMTP ports, or don't allow using an SMTP server other than their own. A lot of mail services, such as Mandrill, Mailgun, Sparkpost, etc. provide both an SMTP server and a REST API for accepting email. Providing a REST API endpoint for accepting email would allow users on such restrictive hosts to be able to use mailtrap, even when they can't use the SMTP server.

Our use case is simple: we want to forward specific types of emails (our example: password reset). We can always classify them based on the subject line, but not on the email address nor the domain. This feature request is to add automatic forwarding based on subject.

Payment by traditional institutional methods is just not possible for many people.

We use a bulk email delivery company as our email campaign gateway (Socketlabs).
I am looking for something that will automate the responses to campaigns - ie. enable some to return
Bounced
Failed
Complaints
Opens
Clicks
The response could be set by mailbox - and perhaps the facility to spread the timing of opens and clicks.

It would be nice to have configuration example for Exim too (only Postfix example is available today).

It will be good to be able to receive bigger emails using mailtrap. Is it possible to increase message limit to, for example, 10MB for paid account?
Or as workaround - allow forwarding of that emails.

Since realtime updates is already implemented, it would be helpful if we could check some checkbox so the inbox always shows the last incoming mail, without the need for me to click it in the message list.

It would be helpful to be able to alphabetically sort the list of inboxes.

Add ability to migrate ownership to another user in company, for example by confirmation email.

SMTP servers forward mail on to BCC recipients while at the same time stripping that field. Because Mailtrap is serving as the SMTP server, it can record the original data in the BCC header.

The default Mailtrap view should continue to hide the BCC header to provide a Client-like view, but the BCC header should be made available in either the RAW view or another view "As Received".

Show SMTP configuration one should use for the current user/company EVERYWHERE