bodybuilder | An elasticsearch query body builder muscle | Search Engine library

Before I explain how to save the message in your Sent IMAP folder, I first want to bring attention to a few things.

1. smtp.Timeout = 10000; It's probably best to not override the default timeout (which I believe is 120,000. 10000 is 10 seconds).
2. You currently have a mix of sync and async calls to the SmtpClient. You should pick sync or async and stick with it (at least if it's all within the same method).

Okay, now on to your question.

Please try to use string[] eMailTo, it should be useful to you.

You're using it wrong :-)

You are trying to decrypt a MIME message stream. You can't do that.

The SecureMimeContext.Decrypt() and DecryptAsync() methods expect the encrypted content of the MIME message.

If your goal is to load the MimeMessage and decrypt it, you would change your code to this:

Directly using providers like Gmail, Outlook and similar ones is not advised because they perform checks that can disrupt your code just like you're seeing here.

This can happen without previous notice. And believe me, it will happen from time to time.

Most providers (Gmail specially) now enforce a web-based flow, from the most recent OAuth/OpenID specifications, for safer authentication/authorization.

This would be my first guess: Gmail auth (which is browser based) is simply blocking your login attempt because it wants you to use a browser and not simply submit your credentials.

There's a lot of background work done by IAM solutions to help protect users, namely called risk assessment. This, in time, might require both captcha and MFA challenges to be sent back to the user, so an API would not really work on this, that's another reason why they focus on browsers and not simply on getting the correct credentials.

Email providers (specially Gmail) are great at detecting possible bots and this would be my second guess: it detected your service as a bot and put a temporary hold on your account to "protect you".

It's possible that this works on lower environments (aka: your machine and/or testing environment) and not production because of the server bot prevention system, which typically inspects IP address, user agent from the browser (if any), API call rate, authentication rate and others.

Yet another thing that can block you when doing such integration is the rate limit. Typically, 500 messages/month.

To workaround this and still use Gmail, this is the way to go: https://support.google.com/accounts/answer/185833?hl=en

It's called application password and is a different password that you generate on your account for a particular app to be allowed signing in. That will skip the OAuth and the bot validation (at least on most cases).

The only reliable way to have this fixed is to use a proper send email service. Something like Amazon Simple Email Service, Sendgrid, or a bunch of others out there.

That's because they are created to be used by API calls and won't get in your way. You can set-up your own domain there, including SPF and DKIM keys so your recipient's email server will recognize the message as safe and indeed as coming from your (and not a random SPAM).

The first thing you'll need to do is to locate the HTML body part.

A quick hack might look something like this:

Netcat works on your Windows machine for the same reason that MailKit works on your Windows machine.

Your Windows machine has an unblock route to the mail server.

Your Ubuntu server, on the other hand, does not have an unblocked route to the mail server, so it fails to connect there.

You need to figure out your firewall and/or routing tables on your Ubuntu server and fix that to allow connecting to the mail server.

If I understood you correctly, you do not like that your rope behaves like rubber or a spring. This has to do with how box2d constraint solver works. For each connection it tries to correct the position of the bodies. Overall, it works out well. But when there are many of connections, it takes time for the solver to put the bodies in correct positions. For this reason, the spring effect arises. To decrease it, you can decrease the simulation time step. This will make the behavior of the connections more accurate, but will increase the CPU utilization. But in your case, it would be best to add another RopeJoint, which would connect the first and the last body of your rope and have a length equal to the length of the rope. This connection will prevent the beginning and end of the rope from moving further than the length of your rope.

I have followed the example in here and I was able to send an email with a PDF attachment with MimeKit using this code:

Based on the documentation, I don't think you need to set the ContentTransferEncoding or ContentDisposition; you should just need to use: