Why is my mail being marked as spam when send via Mvc.Mailer? - email

Question

I am using the Nuget Package Mvc.Mailer to send e-mail to my clients. I followed this guide and I'm encountering one really annoying thing. My sent e-mails are always sent to spam. Here's what my code looks like:
UserMailer:
public virtual MvcMailMessage Authenticatie(User user, string email)
{
ViewBag.User = user;
ViewBag.Email = email;
return Populate(x =>
{
x.Subject = "Your registration at Example";
x.ViewName = "Registration";
x.IsBodyHtml = true;
x.From = "Name <noreply#example.com>";
x.To.Add(email);
});
}
Registration.cshtml:
using Mvc.Mailer
<div>
<p style="display: none">Stuff in my email</p>
<h1 style="background: #e68425; text-align: center; color: white; margin: 0px; padding: 10px;">
A bunch of HTML
</h1>
<div style="background: #cf7721; text-align: center; padding: 10px;">
<h3 style="margin: 0px;">Activate account</h3>
</div>
<div>
<p>Dear client,</p>
<p>
Thanks for bla bla bla... And more stuff.
</p>
<table>
<tr>
<td>Login:</td>
<td>#ViewBag.User.Login</td>
</tr>
<tr>
<td>Activatiecode:</td>
<td>#ViewBag.User.Activation</td>
</tr>
</table>
</div>
Web.config:
<mailSettings>
<!-- Method#1: Configure smtp server credentials -->
<smtp from="Example <noreply##example.com>">
<network enableSsl="false" host="mail.#example.com" port="25" userName="noreply#example.com" password="xxx" />
</smtp>
</mailSettings>
What we have tried
Sending our e-mails via the standard way, with the SmtpClient. This mail didn't go to spam.
Setting x.From to a better name.
Different content types
x.IsBodyHtml = true
Sending an e-mail from our e-mail client (same address). This mail didn't go to spam.
Questions
Could our e-mail be filtered by excessive use of html?
Has anybody encountered this problem before, using this Nuget package?
How can I stop my e-mails from going to spam?
Above all: why are they going to spam?

Answer 1

Try to check all hyperlinks in template. It was just the word "email" in one of my Url.Action for becoming junk.