Electronic mail (email or e-mail) is a method of exchanging messages ("mail") between people using electronic devices. Email entered limited use in the 1960s, but users could only send to users of the same computer, and some early email systems required the author and the recipient to both be online simultaneously, similar to instant messaging. Ray Tomlinson is credited as the inventor of email; in 1971, he developed the first system able to send mail between users on different hosts across the ARPANET, using the @ sign to link the user name with a destination server. By the mid-1970s, this was the form recognized as email.
Email operates across computer networks, primarily the Internet. Today's email systems are based on a store-and-forward model. Email servers accept, forward, deliver, and store messages. Neither the users nor their computers are required to be online simultaneously; they need to connect, typically to a mail server or a webmail interface to send or receive messages or download it.
Originally an ASCII text-only communications medium, Internet email was extended by Multipurpose Internet Mail Extensions (MIME) to carry text in other character sets and multimedia content attachments. International email, with internationalized email addresses using UTF-8, is standardized but not widely adopted.The history of modern Internet email services reaches back to the early ARPANET, with standards for encoding email messages published as early as 1973 (RFC 561). An email message sent in the early 1970s is similar to a basic email sent today.
Hi,
I need to email a professor but his university automatically rejects email like gmail. What email address domain I can get that can pass through his university spam filter and the email reached hiim?
Thank you.
Hi,
A company doesn't have an online store. They accept credit card payment via email or fax. Email is not secure. And I don't have a fax machine.
They don't use viber. What other medium that one can send credit card information except fax. And can't fax be intercepted?
Apprecited and thank...
Ok, so, I guess like just everyone else, I receive a(n) (over)load of spam in my Yahoo/Gmail accounts. Some of the emails offer the option to unsubscribe.Yet when I accept it, I'm asked to provide my email. Is this standard/legit? I suspect these sites use a spambot and generates random...
I recently submitted a self-authored article with no affiliation to a peer reviewed journal, which then got desk rejected. The email however wasn't a generic one; the editor made a comment about its content that clearly indicates he read the whole thing, but he didn't correct me or say anything...
Hi,
I received a scam text with links included on my Android S9 phone. Sender appears as an email address, rather than as a phone number. My texting program allows the blocking of phone number does not include the feature of blocking the originating email address. Any ideas of how else I can...
I tried creating a new Gmail account. I have several that have become de facto defunct (lost passwords with no way to recover). . .
I've noticed every combination of words/letters for my attempted new username entry had been taken. That sucks. I had to literally come up with a stupid...
I am trying setting up flask email for outlook. I had it working with gmail I found this link https://superuser.com/questions/1521236/how-to-allow-less-secure-app-access-in-microsoft-email I tried
MAIL_SERVER= 'smtp.office365.com'
MAIL_PORT = 587
MAIL_USE_TLS = True...
Can i view email address of my WhatsApp contacts?
I am unable to view email address since the signing up was done using phone number by my contacts?
If the Sign up was done by the contact using email address,then i would have been able to view his/her email address ?
Thanks & Regards,
Prashant...
I've been getting emails from an "hq@bill.com" address that have looked suspicious. The titles usually say something like: "Invoice prepared for you and will become payment."
Usually, I just delete them. Today, my mouse/hand slipped and I accidentally hovered over and clicked onto that...
I suck. I NEVER write down my email passwords for fear of them getting stolen.
I created a new password for one of my email accounts today. Already, I've forgotten it. I know very generally what it's "like," but cannot nail down the letters. Worse is that I didn't enter a recovery method...
I often receive a spam email sent to me, Frodo <me@example.com>, and purporting to come from a friend of mine, Tom Thumb, whose ID is Tom <my_friend@anymail.com>.
I am sure it isn't random chance as I don't get similar emails from people I don't know.
How does the spammer work out that
Frodo...
I am writing a java application that would let me bulk send emails.
The first problem I have is that of performance; approximately 15 seconds per 5 emails.
The second problem, which is the more important, is that my JavaFX is not updating the scene. My code below shows that the way I intended...
Hi
I started having problem in keeping my ATT @sbcglobal.net email sign in. It used to be able to choose keep sign in for 2 weeks, I don't have to re-signin for two weeks. But something happened and now I have to sign in every two hours or so even if I check the keep sign-in for two weeks. This...
In order to use the Second Shift Theorem, the function needs to be entirely of the form $\displaystyle f\left( t - 1 \right) $. To do this let $\displaystyle v = t - 1 \implies t = v + 1 $, then
$\displaystyle \begin{align*}
\mathrm{e}^{-2\,t} &= \mathrm{e}^{-2 \, \left( v + 1 \right) } \\
&=...
In order to factorise this quadratic, we will need to recognise that $\displaystyle \mathrm{i}^2 = -1 $, so we can rewrite this as
$\displaystyle \begin{align*} \frac{1}{6 + 5\,\mathrm{i}\,\omega - \omega ^2 } &= \frac{1}{\mathrm{i}^2\,\omega ^2 + 5\,\mathrm{i}\,\omega + 6} \\ &= \frac{1}{...
I'm assuming the hypothesis test is
$\displaystyle H_0 : \mu = 13 \quad \quad H_a : \mu < 13 $
We are given $\displaystyle \mu = 13, \quad \sigma = 2.47, \quad \bar{x} = 12.86 , \quad n = 20 $.
The test statistic is
$\displaystyle \begin{align*} z &= \frac{\bar{x} -...
First we need to write the DE as a system of first order DEs.
Let $\displaystyle u = y $ and $\displaystyle v = y' $. Then
$\displaystyle \begin{align*} x^2\,y'' - 5\,x\,v + 7\,u &= 2\,x^3\ln{\left( x \right) }\\
x^2\,y'' &= 5\,x\,v - 7\,u + 2\,x^3\ln{ \left( x \right) } \\
y'' &=...
We would need to recognise that the integral in the equation is a convolution integral, which has Laplace Transform: $\displaystyle \mathcal{L}\,\left\{ \int_0^t{ f\left( u \right) \,g\left( t - u \right) \,\mathrm{d}u } \right\} = F\left( s \right) \,G\left( s \right) $.
In this case...
Since this is of the form $\displaystyle \frac{f\left( t \right)}{t} $ we should use $\displaystyle \mathcal{L}\,\left\{ \frac{f\left( t \right) }{t} \right\} = \int_s^{\infty}{F\left( u \right) \,\mathrm{d}u } $.
Here $\displaystyle f\left( t \right) = \cosh{\left( 4\,t \right) } - 1 $ and so...
To apply this Runge-Kutta scheme, we will need to write our second order DE as a system of first order DEs.
Let $\displaystyle u = y $ and $\displaystyle v = y' $, then we have
$\displaystyle \begin{align*} y'' + 4\,v - 7\,u^2 &= 0.2 \\
y'' &= 0.2 - 4\,v + 7\,u^2 \end{align*} $
So our system...
The Bisection Method solves equations of the form $\displaystyle f\left( x \right) = 0 $ so we must write the equation as $\displaystyle 11\cos{ \left( x \right) } - 1 + 2\,\mathrm{e}^{-x/10} = 0 $. We can then see that $\displaystyle f\left( x \right) = 11\cos{ \left( x \right) } - 1 +...
The Secant Method is a numerical scheme to solve equations of the form $\displaystyle f\left( x \right) = 0 $, so we must rewrite the equation as $\displaystyle 0 = \frac{1}{2}\,x^2 - 10 - \sin{ \left( 1.8\,x \right) } $.
Thus $\displaystyle f\left( x \right) = \frac{1}{2}\,x^2 - 10 - \sin{...
Alexander asks:
Apply three iterations of Newton's Method to find an approximate solution of the equation
$\displaystyle \mathrm{e}^{1.2\,x} = 1.5 + 2.5\cos^2{\left( x \right) } $
if your initial estimate is $\displaystyle x_0 = 1 $.
What solution do you get?
The Bisection Method is used to solve equations of the form $\displaystyle f\left( x \right) = 0 $, so we need to rewrite the equation as $\displaystyle 8\cos{ \left( x \right) } - \mathrm{e}^{-x/7} = 0 $. Thus $\displaystyle f\left( x \right) = 8\cos{ \left( x \right) } - \mathrm{e}^{-x/7} $...
You first have to write this DE as a system of first order equations.
Note, since $\displaystyle t$ does not appear in the original DE, that means that the system will be autonomous if kept in terms of $\displaystyle t$.
Let $\displaystyle y = u$ and $\displaystyle y' = v$, then...
Take the Laplace Transform of the equation:
$\displaystyle \begin{align*} s\,Y\left( s \right) - y\left( 0 \right) + 11\,Y\left( s \right) &= \frac{3}{s^2} \\
s\,Y\left( s \right) - 5 + 11\,Y\left( s \right) &= \frac{3}{s^2} \\
\left( s + 11 \right) Y\left( s \right) &= \frac{3}{s^2} + 5 \\...
Upon taking the Laplace Transform of the equation we have
$\displaystyle \begin{align*} s^2\,Y\left( s \right) - s\,y\left( 0 \right) - y'\left( 0 \right) + 4\,Y\left( s \right) &= -\frac{8\,\mathrm{e}^{-6\,s}}{s} \\
s^2 \,Y\left( s \right) - 2\,s - 0 + 4\,Y\left( s \right) &=...
This requires the convolution theorem:
$\displaystyle \int_0^t{f\left( u \right) \,g\left( t- u \right) \,\mathrm{d}u } = F\left( s \right) \,G\left( s \right) $
In this case, $\displaystyle g\left( t - u \right) = \mathrm{e}^{-3\,\left( t - u \right) } \implies g\left( t \right) =...
Start by taking the Laplace Transform of both equations, which gives
$\displaystyle \begin{cases} s\,X\left( s \right) - s\,x\left( 0 \right) + X\left( s \right) + 6\,Y\left( s \right) = \frac{6}{s} \\ s\,Y\left( s \right) - s\,y\left( 0 \right) + 9\,X\left( s \right) + Y\left( s \right) = 0...
The Heaviside function suggests a second shift, but to do that, the entire function needs to be a function of $\displaystyle t - 4$.
Let $\displaystyle u = t - 4 \implies t = u + 4$, then
$\displaystyle \begin{align*} \mathrm{e}^{5\,t} &= \mathrm{e}^{5\left( u + 4 \right) } \\ &=...
Below is an email that I am planning to send to someone that I would very much like to work for as a graduate student. Are there any red flags I should avoid? Anything else in particular I should mention? Thanks in advance.
Hello Dr. [REDACTED],
I am an undergraduate physics major (junior)...
Can email spammers alter email headers so that we can't find out which internet service provider and mail server originates their messages?
Sometimes emails sent from a reputable ISP get temporarily blocked by some servers due to complaints about spam originating from the ISP. The sender is...
I'm about done with my mini-vacation posting flurry, but before I get back to work I want to ask one question which may be of interest to lots of forum members. I no longer use Google for search, relying instead on DuckDuckGo. I also have the Tor browser, which I use for logging into my free...
Hi, I have a strange issue, I cannot log into my @sbcglobal.net email on my laptop. I know the password, we have no problem logging in on another computer, just my laptop. I tried using IE and Google Chrome ( going to Yahoo), both kept saying the password or email address are not valid. I tried...
I get a ridiculous amount of gmail every day from my college's student body, but 95% is just students flooding the emails with nonsense ' forum bump' type responses and it's a chore to try and check my emails.
--Does anyone have any idea how to filter out or mute responses to future emails?--...
Hey! I’m writing an email to a professor for research and I am mentioning some things I’ve found interesting and trying to connect them to his research but I’m not exactly sure if I’ve gotten the gist of these topics right ; like for example if dark matter and stuff effects the structure or...
Today my wife received an e-mail, apparently from PayPal, notifying her that a payment was being made from her PayPal account for a purchase of about $30, and with a link to click if she wanted to dispute it. But... she's never opened a PayPal account.
She was using iOS Mail on her iPad. As far...
Hi All,
I remember reading somewhere ( unfortunately can't remember the precise place) about some email program/service that would forward to it , emails from an existing account. Say I have Address1@mail1.com as an existing address. This service, with account , say Address2@mail2.com...
We should note that the two functions intersect at $\displaystyle \begin{align*} x = -\frac{1}{2} \end{align*}$ and $\displaystyle \begin{align*} x = 1 \end{align*}$.
(a) Using the method of washers, the inner radius is $\displaystyle \begin{align*} 3 - \left( x + 1 \right) = 2 - x...
(a) We should recall that for a small change in x, then $\displaystyle \begin{align*} \frac{\mathrm{d}y}{\mathrm{d}x} \approx \frac{\Delta\,y}{\Delta\,x} \end{align*}$, so $\displaystyle \begin{align*} \Delta\,y \approx \frac{\mathrm{d}y}{\mathrm{d}x}\,\Delta\,x \end{align*}$, so in this case...
This requires using Integration By Parts twice...
$\displaystyle \begin{align*} I &= \int{\mathrm{e}^{-2\,x}\cos{ \left( 3\,x \right) } \,\mathrm{d}x} \\ I &= \frac{1}{3}\,\mathrm{e}^{-2\,x} \sin{(3\,x)} - \int{ -\frac{2}{3}\,\mathrm{e}^{-2\,x} \sin{(3\,x)}\,\mathrm{d}x } \\ I &=...
If we remember that the derivative is defined by $\displaystyle \begin{align*} \frac{\mathrm{d}y}{\mathrm{d}x} = \lim_{\Delta\,x \to 0} \frac{y\left( x + \Delta\,x \right) - y\left( x \right)}{\Delta \, x} \end{align*}$ then that means that as long as $\displaystyle \begin{align*} \Delta \,x...