Category Archives: Personal

Gmail, Exim and Let’s Encrypt

上個月 24 號發現不能在 Gmail 選擇用自己的 domain name 的 email 發電郵,發完後 Gmail 會回信報錯:

The response was:

TLS Negotiation failed, the certificate doesn't match the host. 

本以爲 SMTP server 哪裏設定不對,在網上發現不少人跟我一樣有同樣的經歷,原來最近 Google 已不再允許發電郵方使用 self-signed certificate,而我的 certificate 正正就是。由於 web server 一直有用 Let’s Encrypt 來生成 certificate,那就順手用 certbot 再多生成一張 certificate 給 Exim 用,詳細可參考 https://loune.net/2016/02/lets-encrypt-with-exim-and-dovecot/

主要的命令是:

$ certbot-auto certonly --standalone -d mail.example.com

由於 certbot 要用過 mail server 的 port 80 做 authentication,因此需要先把 web server 暫時停掉,每次 renew 也要,可以通過 certbot 的 –pre-hook 和 –post-hook 來做,例如:

$ certbot-auto renew --pre-hook "systemctl apache2 stop" --post-hook "systemctl apache2 start"


Not my first blog

Technically speaking this is not my first blog site but my 3rd one. The first is this one, which could not be classified as a blog in today’s standard, since it is just a static HTML page with plain text only. The second one is this, which is hosted at Debian HK using Drupal as the engine. I started it shortly after the Debian HK site was launched. For the time being, I’ll be using this new blog and the one at Debian HK simultaneously, this one for my daily life and the other one for FOSS and Debian matters, as the latter is linked to Planet Debian HK and I don’t want to “pollute” it with my everyday’s sundry matters :)

Notebook hard disk failed, no 40GB 1.8″ disk in Beijing

The hard disk in my new IBM X40 started misbehaving around 2am last night. Some time earlier it was making rather loud noises. And then two commands (ps and smartctl) locked up the machine and I have to used sysrq magic keys to reboot it. It’s too soon for the harddisk to fail because the notebook was bought in October last year, so it’s about 5 months only. My original plan was to buy a new harddisk, transfer data from the failing one to the new one as much as possible, and then take the failed one to an IBM repair center for a replacement. But the sad news is I could not find a 40GB 1.8″ harddisk (which the IBM X40 can only use, it can’t use the 2.5″ ones) in Beijing’s Zhongguancun(中关村)! Zhongguancun to Beijing is what the Golden computer center to Hong Kong, you go there for any kind of computer hardware and parts. For all the shops I asked which sold 1.8″ harddisk, they only had 20GB. Once again, it proves that if you want to play with the newest electronic toys, your best bet is to try your luck in Hong Kong :|

So bear with me if I’m a bit slow in replying your emails or such, I think I’ll not be back to full force until I can work on my notebook again.