Speed ​​limitation: accelerate outgoing mail per domain in exim

I am using exim to deliver the mail generated by a web application. Two main domains ask me to speed up the amount of mail I send, but I have trouble setting it up in exim.

The scenario is like this:

  1. My web application generates emails
  2. they are sent to exim running on localhost through phpmailer
  3. exim puts them in line immediately
  4. at each run of the queue (every hour) try to deliver the mail
  5. after some successful deliveries, each of these two domains returns a 4xx error code (it will be seen in the records later today) that tells me to send less mail / time

I found a question, but it seems that the acls will limit the speed in step 2 and I don't want that. I want to rate the limit in point 4. And only for the two domains in question.

Error message: How do you communicate to a user that your money will not be available due to a technical limitation?

We have a function that allows the user to add a button where they can accept payments online. Payments are processed through Stripe.

It's quite simple: the user creates a payment button, the user connects to Stripe, the user can start accepting donations.

However, the problem here is that there are certain countries where Stripe is not available. Ideally, we hide this function in countries where Stripe is not available, but There is a technical limitation at the moment when this cannot be addressed.

Here is the scenario:

  1. The user adds a payment button.
  2. A customer of yours makes a payment.
  3. If we detect that this user has integrated with Stripe, the payment appears in your account without any problem.

But, if a Stripe connection is not detected, the user receives an email that says: "You received a donation. To claim your funds, sign up for a Stripe account."

While this would not be a problem for many, since they can only connect to Stripe as next steps, the problem is if / when Stripe is not available in their country, that is: "You have funds, but unfortunately, there is no way to claim them because Stripe is not available in your country. "

What would be the best way to do it?

ddos – Speed ​​limitation API with the PBKDF2 challenge?

Suppose I have a public API endpoint that I would like to protect against abuse. I would like to implement a solution that ensures that the client devotes some computation time before allowing the request to succeed.

What would be the problem of the server choosing a random hash and a variable cost of approximately 200,000, where the server would send the hash and the cost to the client, and the client would have to execute the hash through PBKDF2 200,000 times? What should take a few seconds. The client would then send the result to the server with its request, and the server will verify that 200,000 iterations of the hash match the result of the client.

In theory, this seems to severely limit the number of requests that a spammer can execute.

But the idea sounds too simple to be effective. Am I missing something or would it be a viable solution?

There are two potential problems that occur to me:

  1. The spammer can force our own server to lose calculation time in the calculation of these hash, but we can calculate certain hashes with certain costs and distribute a random entry of our table to any applicant.

  2. Client devices may be less powerful than a potential abuser's machine, so we may require a cost of approximately 2,000,000 to be an effective deterrent, but that cost would be too high for an average client device.

amazon web services – AWS – ELB HTTP traffic limitation

I am running a pretty standard LAMP stack in AWS. ELB distributes traffic to a few instances of EC2 that run the same application.

I have a problem in which I periodically receive a large increase in HTTP traffic from some of my clients. Is there any way (through WAF or something of this nature) to establish regulatory limits? Something similar to if IP X performs 1000 requests in 1 minute to stop traffic from them for a period of time & # 39 ;?

Keep in mind that it is not possible to know in advance the full range of IP of my client, so a solution must be dynamic.

Any guidance on a best practice approach to this problem would be very grateful.

Lottie by Airbnb: Innovation or limitation for designers?

Lottie by Airbnb- What do you think about this animation tool? Have you already tried it?

If you think about trying it and want to know more about applications to create animations Then, in this article, you can find useful information about the pros and cons of using Lottie and how you can help him 🙂


Lottie By Airbnb: Innovation or limitation for designers?

Lottie is a native library of iOS, Android and React that presents animations of After Effects in real time. Lottie allows engineers to create richer animations without the rewrite overload. Do you want to know more about applications to create animations? Then this article is for U))

Have you already worked with him?

Ubuntu 19.04 Changes in multiple monitors could not be saved, could be a limitation of the hardware

I have a Raedon Tahiti HD 7090 – fully compatible hardware. When I try to configure my screens I can not apply the changes because "Changes can not be applied" "This could be due to hardware limitations". All the screens show the background image, but only one is active. I'm trying to convert Windows where this was not a problem.

javascript – Limitation of 6 applications followed in ajax

Hello, I'm doing an application where I make an ajax request to make a record in the bank, the request is working without problems. But I realized that it only accepts up to 6 requests in a row without updating the page after this the server blocks. I am using the nodemon server running on gulp.js

I wonder if this is a standard limitation of the ajax or the browser?

Is it possible to parameterize to increase the number of applications followed or decrease?

Here is the ajax petition

                () () () () ()
let date = $ (& # 39; # form-student & # 39;). serialize ();
console.log (data);

const register = $ .ajax ({
method: "post", "
url: "/ students / register / save",
dataType: "json",
date: date

register.done ((answer) => {
console.log (answer)

return false;

Controller that records data / students / register / save

                module.exports = () => {
return {
register: (req, res) => {
Date =
name: req.body.name,
In this case,
In this case,
(in English): parseInt (req.body.turma_id)


console.log (data)

Aluno.create ({
AL_NAME: data.name,
AL_IDAD: data.age,
AL_OBS: data.obs,
AL_TURMA: fecha.turma

res.status (201)


The application is working only to know about the limitation of the application for curiosity purposes and future projects

dnd 5e – How would you unbalance the gameplay to eliminate the limitation "requires a free hand to charge" for hand crossbows?

I am working on statistics for the royal guards of a home capital, using the Captain Guard as a template. I gave them a hand crossbow and the feat of Crossbow Expert, thinking that it would allow them to hold a shield in one hand and a crossbow in the other.

Crossbow expert mentions in PHB p. 165:

You ignore the load quality of the crossbows. with which you are competent.

• Being less than 5 feet from a hostile creature does not impose disadvantages on your ranged attacks.

• When you use the Attack and attack action with a one-handed weapon, you can use an additional action to attack with a hand crossbow that you have.

At first I thought that would be enough to use a shield while attacking with a hand crossbow, but the Loading the property actually says:

Due to the time required to load this weapon, you can fire only one piece of ammunition when you use an action, bonus action or reaction to shoot it, regardless of how many attacks you can normally do.

So "load" refers to the loading speed, and the feat makes you faster. Is the Ammunition property that, by RAW (PHB page 146), does not allow to hold a shield while attacking and reloading a hand crossbow:

[…] Removing ammunition from a quiver, box or other container is part of the attack (You need a free hand to load a weapon with one hand.). […]


How to unbalance the game to eliminate the limitation "requires a free hand to charge" for hand crossbows? Thematically, it makes sense, because in my environment this city is rich enough to have a technology as sophisticated as the "semi-automatic" hand crossbows (however, that would work). Given that my world configuration allows it, it would be fair if it were also an option for PCs, if they acquire that type of weapon and / or training. I am more interested in the combination of shield and crossbow hand, but if I forget other possible feats that could unbalance the game, inform me.

I'm fine with allowing it for NPCs (for my guards) because I can calculate the new CR, based on an increase in DPR and AC. As DM I have enough control to maintain that Balanced on the table. By allowing it for PC. although fine, I'm not sure what unbalanced farms I might be overlooking. A good response includes an analysis of the mechanical costs and benefits for PCs when the limitation "requires a free hand to load" is removed.

To eliminate this limitation, I am thinking of three possible ways:

  1. Adjust the ownership of hand-held crossbows munitions specifically.
  2. Adding a feature to the Crossbow Expert feat.
  3. Solve it through magic by making the extravagant crossbows of the royal guard unusual magical weapons that can be recharged without having a free hand.

A surprising answer includes an analysis of the balance of the game in these possible solutions as well.

Is there any limitation to attack while you fight?

I tried to look in other publications about my question, but I could not find a definitive answer to my question.

  • If a level 5 barbarian equipped with a 2-handed weapon attempts a fight and succeeds, will the additional attack feature allow an attack with the 2-handed weapon?
  • The next turn of the barbarian is approaching, can he still make 2 weapon attacks without breaking the hook?

The rules for the fight establish that whoever starts the fight needs at least one free hand, so it has been confusing for me …