How Do Mail Servers Work?


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I get this will vary wildly but on the whole, how do they work?

 

Say I email myself a file (no other way to transfer it home!).

If the mail server doesn't deliver it straight away, what happens then?

 

I've been emailing myself lots of files recently, some come through straight away but it seems when one is delayed, it's a bit like a traffic jam and they're all delayed. But then they come through in a seemingly random order over the period of a few days.

 

Does the server put the delayed email to the back of the queue, or does it count 2 days before trying again?

 

I guess the amount of emails being sent/received on the server affects it too?

 

Thanks

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It would depend on the specific setup.. But yes depending on the failure mode the MTA (mail transfer agent) will back off and try again..

 

https://docs.microsoft.com/en-us/exchange/mail-flow/queues/message-intervals?view=exchserver-2019

 

 

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Transfer of anything other than the smallest of files in email is not really a good method no matter the email servers in use.

 

You want to include a few pictures, or a zip ok sure - but sending many files via email is prob not the best course of action.

 

What are the size and types of files your sending - are you using a local mail server, or sending to a provider of email - your isp, google, yahoo, etc. ?

 

But sure once a backup log happens, and depending on the failure reason for the different sending of emails - sure its possible the order of transfer could become out of sync with the time sent/recv'd by the different servers in the path of sending..

 

If your goal is the sending of large amount of files or large files it would be better course of action to find a more suitable form of transfer.

I know your initial question was about how emails work. Given that you're sending a large number of files and regularly (at least it seems), wouldn't some kinda cloud storage be better. Heck if you're sending them to yourself, even a USB would suffice.

 

Any particular reason you're using email instead?

And if you want to set up your own mail server like I once did (I since have high-tailed it to a MSP), you'll have to do things with certain major mail providers promising to abide by their rules to ensure the delivery of mail from your server. Examples are Microsoft, I signed an agreement to stop spam, etc. After I did that, 24 hours later, mail from my server was finally delivered to outlook.com.

 


I do not envy mail server administrators and sysadmins.

Sorry for being slow on the reply.

 

I am backing up some documents, only PDF, but some end up being about 5MB each.  Others 2 or 3.

 

I don't have a scanner so thought I'd use the one at work.
The scanner has a USB port, which is disabled.
The PC has a USB port, which is disabled.

My work use Lotus notes (el cheapo I know!)

The scanner won't allow me to send direct to my email / outside of the company.

 

The work PC is a retail PC, so they don't really allow you access to Computer or Documents or anything.  I can save a document locally, but as soon as I go to find it, it's not there.

 

So I can't figure out another way to send documents elsewhere.

Log and drawn out but I'm just over half way through now.  I generally send one and wait for it to come through, then send another.

 

While I'm not at Expert level of IT, it's been interesting trying to find a way round all the restrictions.

4 hours ago, Sir Topham Hatt said:

I don't have a scanner so thought I'd use the one at work.

You know you can get an all in one printer, that does scanning/copy normally with a document feeder even for under a $100 right ;)

 

Vs jumping through all these nonsense hoops... It would be one thing if you need a 1 time scan sort of thing.. But clearly you have a lot of stuff you want to scan and save as PDF.. So why would you not just get a tool that you can use when you want, how you want and not have to jump through all these hoops..

 

Here is one for $50

https://www.amazon.com/Canon-MX492-Wireless-Printing-Compatible/dp/B00RN08584

I agree; I good all-in-one (or a stand alone scanner if you already have a printer) will keep you covered for future document backup needs as well

 

sounds like it would be much less hassle then trying to transfer the documents from your work PC

 

(plus I know a lot of work places frown on using their scanners/printers for personal use like you are doing. just an fyi as I don't want you accidentally getting in trouble with your job)

You must understand that corporate mail servers work in a lot of different ways.  Your company may require managers approval for sending information to outside, this is not something you as the end user would be aware of.   Your mail server may have an issue with attachments over a certain size causing mail to go out.  In an unconfigured/uncustomized state, mail is first come first serve.  Your company may have multiple mail servers that send out mail if one is busy/taking too long, your message may jump around the queues for a bit until one becomes available (but this is usually pretty fast, not days).  Days could mean that it getting stuck in a queue or your manager isn't releasing it/approving it to be sent out.  Days could also mean that there is an issue with a mail server and cannot receive or send.  Out of order could be size related and stuck in the antivirus queue (these can slow mail down quite a bit).

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