Some of our clients are experiencing delivery issues to some domains that use Gmail/Google for their email.
I previously covered that here – http://www.computersolutions.cn/blog/2015/04/gmail-and-other-google-hosted-mail-delivery-issues/
The issue is that China is still blocking Gmail/ Google hosted mail, and the recipient domain hasn’t setup their MX records correctly.
This is fine for servers outside of China, where all of googles mail servers (should) work, but breaks things for those inside China, where only a few servers are reachable.
Google hosted mail settings are here: https://support.google.com/a/answer/33915?hl=en
You’ll note that there are 5 different email servers that are listed in priority order.
Priority Mail Server
1 ASPMX.L.GOOGLE.COM.
5 ALT1.ASPMX.L.GOOGLE.COM.
5 ALT2.ASPMX.L.GOOGLE.COM.
10 ALT3.ASPMX.L.GOOGLE.COM.
10 ALT4.ASPMX.L.GOOGLE.COM.
For mail servers, the higher number is more important, so a priority of 1 will be the first server tried, then the next highest number, and so on.
If I try to connect to the servers from China.
telnet ASPMX.L.GOOGLE.COM 25
Trying 74.125.200.27…
(times out)
telnet ALT1.ASPMX.L.GOOGLE.COM 25
Trying 173.194.72.26…
(times out)
telnet ALT2.ASPMX.L.GOOGLE.COM 25
Trying 74.125.25.26…
(times out)
telnet ALT3.ASPMX.L.GOOGLE.COM 25
Trying 64.233.169.26…
Connected to ALT3.ASPMX.L.GOOGLE.COM.
Escape character is ‘^]’.
(yay, we have a winner!)
telnet ALT4.ASPMX.L.GOOGLE.COM 25
Trying 74.125.70.27…
Connected to ALT4.ASPMX.L.GOOGLE.COM.
Escape character is ‘^]’.
(yay, we have a winner!)
So, we can see that alt3, alt4 work, but none of the others do (as of 9th September 2015 from Shanghai)
So, some rudimentary testing shows that some servers work, and some do not.
How does that apply to real world examples.
Lets look at a non-working domain – ihg.com
dig mx ihg.com
;; ANSWER SECTION:
ihg.com. 600 IN MX 100 aspmx3.googlemail.com.
ihg.com. 600 IN MX 50 alt1.aspmx.l.google.com.
ihg.com. 600 IN MX 50 alt2.aspmx.l.google.com.
ihg.com. 600 IN MX 100 aspmx2.googlemail.com.
ihg.com. 600 IN MX 10 aspmx.l.google.com.
You should easily be able to see 2 things.
1 – that the MX records are not as per Google settings.
2 – that the 2 working MX records are not listed.
This means that while their MX records probably work oversea’s, they will not be deliverable from China. They need to amend their MX records to Googles recommended settings.
Lets look at another example.
dig mx rsms-west.com
;; ANSWER SECTION:
rsms-west.com. 6238 IN MX 30 alt2.aspmx.l.google.com.
rsms-west.com. 6238 IN MX 10 aspmx.l.google.com.
rsms-west.com. 6238 IN MX 40 aspmx2.googlemail.com.
rsms-west.com. 6238 IN MX 50 aspmx3.googlemail.com.
rsms-west.com. 6238 IN MX 20 alt1.aspmx.l.google.com.
Once again, we can see that the alt3, and alt4 servers are missing, and unfortunately none of the other listed servers are connectable from China.
Lastly, lets look at a working server
dig mx teamsequel.com
teamsequel.com. 12878 IN MX 1 ASPMX.L.GOOGLE.com.
teamsequel.com. 12878 IN MX 5 ALT1.ASPMX.L.GOOGLE.com.
teamsequel.com. 12878 IN MX 5 ALT2.ASPMX.L.GOOGLE.com.
teamsequel.com. 12878 IN MX 10 ALT3.ASPMX.L.GOOGLE.com.
teamsequel.com. 12878 IN MX 10 ALT4.ASPMX.L.GOOGLE.com.
You can see that they have the correct Gmail settings as per Gmail / Google settings page, and mail to them is deliverable (as alt3, alt4 are currently not being blocked by the beneficent government of China).
Unfortunately as this is an issue that is out of our control (MX records are incorrect, and China is being difficult), we cannot mitigate against it. The affected domains will need to amend their MX records appropriately as per the page here- https://support.google.com/a/answer/33915?hl=en.
Update
Google has added another MX (mail server) for Google Hosted mail – alt4.gmail-smtp-in.l.google.com.
This does not currently appear to be blocked (unlike their other 4 MX servers), so we have removed the forwarding, and mail is transiting normally.
China has completely blocked gmail hosted mail as of today [28th April 2015]
This means that all mails heading to google’s servers is now blocked from Chinese ISP’s like ourselves.
Symptoms will include bounce messages where our server has given up retrying to send out the mail, as the remote server is not accessible over the Chinese internet.
EG –
Hi. This is the qmail-send program at mail.computersolutions.cn.
I’m afraid I wasn’t able to deliver your message to the following addresses.
This is a permanent error; I’ve given up. Sorry it didn’t work out.
:
Sorry, I wasn’t able to establish an SMTP connection. (#4.4.1)
I’m not going to try again; this message has been in the queue too long.
In the interim, we have added forwarding for all gmail addressed mail to transit through our oversea’s mail servers in the USA.
This should solve email delivery issues for gmail addresses – essentially anything addressed to someone @gmail.com
We are looking at solutions for resolving delivery to other google hosted mail clients, this will take some time to come up with a usable solution. In the interim, we can manually add routes on a server by server basis.
Be aware that this specific issue is out of our control, and we can only mitigate against it.
Examples of google hosted mail clients from recent queries/failure notices:
teamsequel.com – Their mail is served by google.
dig mx teamsequel.com
; <<>> DiG 9.8.4-rpz2+rl005.12-P1 <<>> mx teamsequel.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 11757 ;; flags: qr rd ra; QUERY: 1, ANSWER: 5, AUTHORITY: 2, ADDITIONAL: 0 ;; QUESTION SECTION: ;teamsequel.com. IN MX ;; ANSWER SECTION: teamsequel.com. 2320 IN MX 5 ALT1.ASPMX.L.GOOGLE.com. teamsequel.com. 2320 IN MX 5 ALT2.ASPMX.L.GOOGLE.com. teamsequel.com. 2320 IN MX 10 ALT3.ASPMX.L.GOOGLE.com. teamsequel.com. 2320 IN MX 10 ALT4.ASPMX.L.GOOGLE.com. teamsequel.com. 2320 IN MX 1 ASPMX.L.GOOGLE.com.
dreamonproductions.com – their mail is served by google.
dig mx dreamonproductions.com
; <<>> DiG 9.8.4-rpz2+rl005.12-P1 <<>> mx dreamonproductions.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 35828 ;; flags: qr rd ra; QUERY: 1, ANSWER: 5, AUTHORITY: 0, ADDITIONAL: 0 ;; QUESTION SECTION: ;dreamonproductions.com. IN MX ;; ANSWER SECTION: dreamonproductions.com. 3600 IN MX 5 alt1.aspmx.l.google.com. dreamonproductions.com. 3600 IN MX 1 aspmx.l.google.com. dreamonproductions.com. 3600 IN MX 10 aspmx2.googlemail.com. dreamonproductions.com. 3600 IN MX 5 alt2.aspmx.l.google.com. dreamonproductions.com. 3600 IN MX 10 aspmx3.googlemail.com.
As I’m currently in the airport, waiting for a flight back to the UAE, I thought I’d share this small snippet of transparency vs secrecy.
As most China users will know, there is no official agency that “blocks” websites. In fact, most of the time, the government states that sites are not blocked, despite fairly obvious proof to the contrary.
China typically asserts that “connection resets” to sites like Facebook and Youtube are just network issues, despite those network issues solely appearing at the ip addresses associated with the government firewalls at the gateway routers to overseas.
Here in the UAE (Dubai), the government still blocks, but at least they’re upfront about it:
See below for an example of a blocked site
Why is this important?
Transparency is a big problem for western entities doing business in China. As with the recent Google PR stunt/debacle, most companies have no real mechanism for dealing with arbitrary judgements for / against things that affect their business.
A clear and transparent mechanism for dealing with why sites are blocked, coupled with a delisting mechanism would be a good place to start. It would also help to defuse the detractors against censorship – although most countries censor, China is one of the usual scapegoats picked on.
Maybe if China implemented a what (was blocked) / why (it was blocked) / how (to get unblocked) system, detractors would have less to complain about.
Lawrence.
14
SEO
While I personally feel that a lot of SEO (Search Engine Optimization) is hogwash, there are basic tenets to building well indexed sites.
The usual common sense ones apply –
- Making sure Page Titles are clear.
Don’t forget to add relevant page descriptions to each page. - Making sure that content is relevant.
Lack of content is the number one issue most clients have. They want to score highly in search engines, but they don’t have any relevant content. This one is easy to solve, although it takes some time. Identify keywords that you want to be found by, and create content that includes those words.I also advise clients to take a look at their competition, and see who scores highly for the words that they want to be found under. Read more »
Archives
- November 2024
- November 2019
- October 2019
- August 2019
- April 2019
- February 2017
- September 2016
- June 2016
- May 2016
- September 2015
- August 2015
- June 2015
- April 2015
- December 2014
- October 2014
- September 2014
- July 2014
- June 2014
- April 2014
- October 2013
- July 2013
- May 2013
- April 2013
- March 2013
- January 2013
- December 2012
- October 2012
- August 2012
- July 2012
- June 2012
- May 2012
- April 2012
- March 2012
- December 2011
- November 2011
- October 2011
- September 2011
- July 2011
- May 2011
- April 2011
- March 2011
- February 2011
- January 2011
- December 2010
- November 2010
- October 2010
- September 2010
- August 2010
- July 2010
- June 2010
- May 2010
- April 2010
- March 2010
- February 2010
- January 2010
- December 2009
- November 2009
- October 2009
- May 2009
- April 2009
- March 2009
- February 2009
- January 2009
- December 2008
- November 2008
- October 2008
- September 2008
Categories
- Apple
- Arcade Machines
- Badges
- BMW
- China Related
- Cool Hunting
- Exploits
- Firmware
- Food
- General Talk
- government
- IP Cam
- iPhone
- Lasers
- legislation
- MODx
- MySQL
- notice
- qmail
- requirements
- Reviews
- Service Issues
- Tao Bao
- Technical Mumbo Jumbo
- Things that will get me censored
- Travel
- Uncategorized
- Useful Info