A Docker IMAP server for repeat-testing INBOUND email? Reverse mailhog? - docker

Woo-hoo! Thanks that we have mailhog for reliable Docker-based testing environments for outbound mail ... allowing us to easily debug mail-sending services without bothering production users ...
... but what about inbound emails?
On one of our sites, users can send an email to a designated support-address and their email will automagically be entered into a ticket system. (As you can well imagine, I am now tasked with replacing that system.) So, is(n't) there already a sort of "reverse mailhog" system, which would allow me to define an "incoming-mail server" which I could from time to time say "had just received thus-and-so message?"
Since this now seems to me to be "just as obvious a requirement as the one 'mailhog' so adroitly solved," I now ask the community – am I overlooking something wonderful that I literally don't yet know about? (Pretty-please tell me in your reply that the answer is 'yes.')

Related

emails sent from production server end up in spam

I use sendmail to send emails from my application. I always send the emails from SOME_NAME#MY_DOMAIN.com but they always endup in spam folder.
I know that I should do some stuff on the DNS side to make my emails be marked as non-spam, but I don't know what they are.
I am a newbie and this is my first time setting up a production server, a domain and everything else myself. I appreciate if someone helps me.
What sort of environment are you deploying to?
This frequently happens to applications deployed to cloud services, like Amazon or RackSpace. Their entire IP blocks are registered as spam at services like Spamhaus, which is a sensible precaution or else we'd be getting even more spam than usual. You should enter your server's IP address in that field to see if you're listed as a spammer.
If you are, you can request to Spamhaus that the block be lifted. Getting in touch with Amazon's support stuff also helps. Finally, you can get around the issue entirely by using a sendmail service of some sort -- Amazon SES is pretty good, and there's even a Gem out there that provides integration to Rails apps.

Rails 3.0 Mass Email

I'm building a web application were users need to ability to send out mass emails. The application is a ticket site where individuals sell tickets to various events. In turn, events have promoters that sell tickets. The sponsor of the event needs to ability to send mass emails to their promoters. An event may have hundreds of promoters. So I'm assuming looping through each promoter and sending an email wont cut it.
Does rails 3.0 provide some kind of mass email functionality?
Thanks,
Brian
I don't think you should have a problem looping through all the promoters and sending each one an email. However, you would want to do that as a background process.
Check out delayed-job or http://www.simpleworker.com/. Both of these will let you load the email into a background job, and allow you to redirect the user in a timely manner while the emails get sent in the background.
Solomon is right, you'll definitely want to do this in a background task, which is pretty simple with something like delayed job. Have you thought about how the messages will actually be delivered though? What mail server you are going to use? Many providers won't let you send out hundreds of messages at a time, and you are likely to run into spam issues if you try to send that volume of messages from a personal email account. You may want to take a look at a service like Mailgun that specializes in this. From their FAQ:
Why not just use Sendmail + Postfix + Courier IMAP?
You can but you should be aware that there is a constant battle raging
between good and evil (i.e., spam) in the email universe. In order to
be on the 'good' side of that battle and get your email delivered
there are numerous things you need to do. You need to have the right
infrastructure and register your IP and Domain appropriately. Also,
you need to have a history of email sending that complies with ESPs
rules in order to build a good reputation.
Moreover, if you are going to receive, store and host emails, you
better be prepared for maintaining this orchestra of software, take
care of backups, hardware failures, security patches and monitoring.
Stop kidding yourself, it's not 1998 anymore.
I'm not affiliated with them in any way, but in my experience getting rails to send email is trivial compared to dealing with getting it delivered successfully by the mail server.

reaching Gmail SMTP daily limit

In one of my Rails applications I'm sending emails through the Gmail SMTP server and everything just works, mails are not going to spam and so on ... But there's one thing that concerns me, the 500messages/day limit the SMTP has, currently I'm over 350/day. I didn't find any official Google page where they talk about the subject, just blog posts that seems to be reliable. Then my question is what do you suggest me in order to be able to send more than 500messages/day? I would love to keep using the Gmail SMTP.
Any help would be appreciated.
Don't use GMail for what it wasn't built for. It wasn't designed as a mass-email system, although Google definitely has the firepower to do this.
Instead, perhaps use something like SendGrid to send your emails. SendGrid is designed for this and is just as easy (actually, probably easier) to set up with than GMail.
You can consider using more than one gmail account to access the smtp server, however you may have problems with ip limits (couldn't find anything on their docs about it). Another option is performing dns mx lookups yourself and reproducing your own smtp server by directly delivering the messages to the user's emails - but that can increase the odds of you being tagged as a spammer as your ip is not whitelisted as sender.
I think the best way is to create another gmail account and trying to reroute your connection to use it when one of the accounts reaches the daily limit. A vpn connection can solve that for you.

Receive mail in Ruby/Rails

How would i go about to receive mails in a Ruby on Rails application without going through a mail server like PostFix or to fetch them by pop3 etc.
What i was to do is to catch all mails sent to #mydomain.com and just do something with them in my application. I don't need to store the mails or anything like that.
Is this posible?
I just implemented this for my SAAS to autoprocess mailer-bounce notification messages.
Call me, call you?
You call me
You can set up a local mail server. It would then respond to an incoming email, and start up a rails executable to process the email. This method is NOT recommended since starting up rails is a big task (takes multiple secs and lots of memory). You don't want a Rails bad boy started up just because you received an email. You'd be writing your own DDOS attack. (Attacking yourself.)
I call you
Instead, poll for email on your own schedule by using a single job to process all currently waiting emails. You need to set up a background job handler since stock rails is focused on responding to web requests. I use delayed_job, but there are other alternatives including kicking off a cron job every so in often.
Another benefit is that you don't need to manage a mail server. Leave that headache to someone else. Then use the Ruby library net::imap to read the incoming mail and process it.
If your process doesn't recognize the email format, then forward the msg to a human for processing.
And be sure that if the process sends mail in addition to reading/processing it, that the process uses a different email address as its From address. Otherwise, odds are good that sometime along the way, you'll end up in an email loop and many gigabytes of messages going back and forth. For example, your process receives a message, responds to it, but in the meantime the sender (a human) has switched on vacation response. And your robot then responds to the vacation response..... oops....
Writing your own mail server
Re:
How would i go about to receive mails in a Ruby on Rails application without going through a mail server like PostFix or to fetch them by pop3 etc.
What i was to do is to catch all mails sent to #mydomain.com and just do something with them in my application. I don't need to store the mails or anything like that.
Direct answer: Yes, you could do this by writing an smtp server and setting up dns so your machine will be the mail destination for the domain. Your smtp server would process the messages on the fly, they would not be stored on your system at any point.
Is this a good idea? No, not at all. While appearances may be to the contrary, email is a store and forward system. Trying to avoid storing the messages before your app processes them is not smart. It would be a very very poor "optimization." However, using an access protocol (POP3 or IMAP) is a good way to avoid the costs of installing, configuring and managing a mail server.
You can do this if you write your own mail server, or if your mail server supports hooks to run external programs upon receipt of mail (e.g. procmail).
If you don't have procmail available (or, if on something like Exchange Server, don't feel like writing custom rules or extensions), you're simply better off using a pop3 library to fetch mail.
Obviously, writing a mail server is more difficult than any of the alternatives.
If you're mostly worried about checking potentially hundreds of email accounts, that's solvable by configuring your email server properly. If you're on a hosted provider, ask your server administrator about creating a "catch-all" account that routes all mail to unknown addresses to a single account.
If you're aiming to avoid having to poll a server, consider the IMAP IDLE command. I've successfully written a Ruby client that opens a connection to an IMAP server, and gets told by the server when new mail arrives.

Is it okay for my online store to send order confirmation emails via Gmail synchronously?

When a user completes an order at my online store, he gets an email confirmation.
Currently we're sending this email via Gmail (which we chose over sendmail for greater portability) after we authorize the user's credit card and before we show him a confirmation message (i.e., synchronously).
It's working fine in development, but I'm wondering if this will cause a problem in production. Will it require making the user wait too long? Will many simultaneous Gmail connections get us in trouble? Any other general caveats?
If sending the emails synchronously will be a problem, could someone recommend an asynchronous solution (is ar_mailer any good?)
The main issue I can think of is that Gmail limits the amount of email you can send daily, so if you get too many orders a day it might break.
As they say :
"In an effort to fight spam and
prevent abuse, Google will temporarily
disable your account if you send a
message to more than 500 recipients or
if you send a large number of
undeliverable messages. If you use a
POP or IMAP client (Microsoft Outlook
or Apple Mail, e.g.), you may only
send a message to 100 people at a
time. Your account should be
re-enabled within 24 hours. "
http://mail.google.com/support/bin/answer.py?hl=en&answer=22839
I would recommend using sendmail on your server in order to have greater control over what's going on and don't depend on another service, especially when sendmail is not really complicated to set up.
The internet is not as resilient as some people would have you believe, the link between you and GMail will break at some point or GMail will go offline causing the user to think that they have not paid sucessfully.
I would put some other queue in place, sendmail sounds acceptable and you can't create your site now for where it 'might' be hosted in the future.
Ryan
If the server waits for the email to be sent before giving the user any feedback, were there problems connecting to the mailserver (timeouts, server down etc) the user request would timeout too and he wouldn't be told anything about the status of his order, so I believe you should really do this asynchronously.
Also, you should check whether doing that is even allowed by GMail's TOS. If that's not the case, you may check if that's allowed if you purchase one of their subscriptions. Also, there's surely a limit to the number of outgoing emails you may send within a given timeframe so if you're expecting your online store to be successful, you may hit that limit and bump into some nasty issue. If you're not self-hosting the site, you should check whether your host offers email servers (several plans include them for free) as then using your host's ISP would be the most obvious choice.
FACT: Gmail crashes. Not often, but it happens, and you can't control it or test it.
The simplest quick-fix is to start a separate thread or fork a subprocess to send the email. Yes, there likely will arise problems from using Gmail, and I really have no input on that vs. the alternatives. But from a design perspective, there's just no reason to make the user wait for that process to complete.
From a testing perspective, this might be where a proxy pattern might come in handy. It might be easy for you to directly invoke Gmail to send a message. Make it harder. Put in a proxy object that does the mailing for you that you can turn off (because heaven knows you can't for testing purposes make Gmail crash). Just make your team follow what happens in the event of an email malfunction by turning off the proxy and trying to complete an order. If you are doing it synchronously, then all the plagues mentioned here by other posters will rear their heads. If you are doing it asynchronously, you should be able to allow it to fail silently (from the user's perspective--from your perspective there should be enormous logging statements and text messages in the middle of the night and possibly a mild electric current arcing across the surface of someone's skin).

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