Gmail advertises:
…and their megabyte counter grows continuously. But when will Gmail reach Webmail.us’s 5GB?
Well, Gmail’s current growth rate is 0.4 MB per day. That means Gmail will reach the 5GB milestone in 5,925 days — October 21, 2022.
I think we have finally worked out all of the bugs with the new POP3/IMAP Proxy Software. The main symptom was when using SSL, saving to the Sent folder would occasionally break. Here were the fixes. Thanks Timo!
So, if you’re a Webmail.us customer and you’d like to help us test, please switch your POP3 or IMAP server to: beta.webmail.us
You should expect everything to work normally. If you see any differences or encounter any problems, please shoot me an email. In the email include whether you are using POP3 or IMAP, and connecting with SSL, TLS or plain-text, and also what mail program and version you are running.
If you try it and do not encounter any problems, I am also interested in hearing from you.
Thanks!
This week we added a pair of load balancers to our email hosting system to balance our internal system traffic such as DNS, LDAP MySQL, and a few other services. Until now we had only used load balancers to balance our external customer traffic (SMTP, POP3, IMAP, Webmail).
Up until now we had our internal services hosted on many independent pairs of servers with master-master failover via heartbeat. With heartbeat, when there is a problem with one server in a pair, heartbeat tells its partner to take over all traffic for the pair until the problem is resolved. Master-master pairs can be tricky however, because it is difficult to catch and handle all possible failure conditions. Plus when a member of a pair dies, fixing it is extremely time sensitive since your service will be down if the other member dies before you restore the redundancy.
It is also messy to scale services that are configured for master-master failover because your application servers need to be configured to each query different database servers, DNS servers etc. It would be a lot cleaner if the applications could simply be told to "query DNS" and something external to the application server routes the query to the right place. That is where load balancing comes in.
Now all of our application servers have identical configurations. They all query the same DNS server, the same LDAP server, and the same MySQL server. However the "server" that they are configured to query is actually a pair of load balancers which redirect the query to one of the real servers behind it. When there is a problem with one of the real servers, the load balancers simply stop sending queries to the bad server. And to scale, we simply add a new real server and tell the load balancer about it.
Our load balancers are custom-built AMD Opteron Dual Core servers with gigabit NICs. They run keepalived, which uses IPVS for load balancing and VRRP for making the load balancers themselves redundant.
Keepalived out of the box only supports load balancing TCP traffic though, so we had to hack it to do UDP for DNS. I’ll save that for another post.
Spammers are an odd bunch. I assume they were just probing to see if my email address was valid when I received this creative message a minute ago:
Subject: xaiedu
Fifteen birds in five firtrees, their feathers were fanned in a
fiery breeze!
But, funny little birds, they had no wings!
I’ve spent a good amount of time trying to find certain features in OpenOffice. These are features that I commonly used in Microsoft Word or Excel, but were difficult to find in it’s open-source equivalent. Maybe I’ll save a few people some time:
Brian H just told me that Insert Page Break is Insert > Manual Break. Lol, must have missed that.
Today I spent some time compiling a list of all of the RFCs that our email hosting system supports. See any I might have missed?…
1939 - POP3
2449 - POP3 Extension Mechanism
3501 - IMAP4rev1
2683 - IMAP4 Implementation Recommendations
2180 - IMAP4 Multi-Accessed Mailbox Practice
2088 - IMAP4 non-synchronizing literals (LITERAL+)
2177 - IMAP4 IDLE command
2342 - IMAP4 Namespace
2087 - IMAP4 QUOTA Extension
3348 - IMAP4 Child Mailbox Extension
3502 - IMAP4 MULTIAPPEND Extension
3691 - IMAP4 UNSELECT command
2221 - IMAP4 Login Referrals
draft - IMAP4 Extension for SASL Initial Client Response
2821 - SMTP (updated rfc821)
3463 - SMTP Enhanced Mail System Status Codes
3464 - SMTP Delivery Status Notifications
2554 - SMTP Extension for Authentication
2920 - SMTP Extension for Command Pipelining
3207 - SMTP Extension for TLS
1870 - SMTP Extension for Message Size Declaration
1652 - SMTP Extension for 8bit-MIMEtransport
2476 - SMTP Message Submission (port 587)
1945 - Hypertext Transfer Protocol -- HTTP/1.0
2616 - Hypertext Transfer Protocol -- HTTP/1.1
2822 - Internet Message Format (updated rfc822)
2045..2049 - Multipurpose Internet Mail Extensions (MIME)
2183 - Content-Disposition MIME header
1894 - Message Format for Delivery Status Notifications
2298 - Message Format for Message Disposition Notifications
3503 - Message Disposition Notification profile for IMAP
3462 - Multipart/Report Content Type
3834 - Automatic Responses to Electronic Mail
2246 - The TLS Protocol Version 1.0
2595 - Using TLS with IMAP and POP3
2142 - Required abuse@ Mailbox Name
4408 - Sender Policy Framework (SPF) Version 1
An opinion held by some anti-spam experts is that "Email is Broken". These folks want to fix the spam problem by completely overhauling the Internet’s email systems and replace SMTP with new protocols that will not allow spammers to pollute the inbox. They compare email to protocols such as Usenet NNTP, which was abandoned by the average Internet user years ago because it lacked simplicity and was not a very powerful way to share information and files, when compared to other web tools such as discussion boards, BitTorrent and blogs. Or FTP which was abandoned by tech-savvy folks who know it’s security risks.
Replacing today’s email protocols with something new would be a great solution if email was indeed broken… But it is not.
Email’s success is based on the fact that it is open and simple. Everybody can understand it, so everybody uses it, and that is what makes it so powerful. Replacing the simplicity of today’s email protocols with something more secure yet more complicated, will break the very thing that makes email great.
Keep that in mind when you are building your killer anti-spam solution. We are.