Hello @aaPanel_Jose , @aaPanel_Kern
I'm facing problem installing mail server . actually it was working good but now i cant send or receive mail. and i tried to reinstalling but it shows postfix stopped.
Image Of Installed Mail Sys
Mail_Sys Installing Log
2024-04-26 20:56:33 (163 KB/s) - '/www/server/panel/plugin/mail_sys/mail_sys_main.py' saved [112840/112840]

--2024-04-26 20:56:33--  https://na1-node.bt.cn/install/plugin/mail_sys_en/services_file.txt
Resolving na1-node.bt.cn (na1-node.bt.cn)... 128.1.164.196
Connecting to na1-node.bt.cn (na1-node.bt.cn)|128.1.164.196|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 2953 (2.9K) [text/plain]
Saving to: '/www/server/panel/plugin/mail_sys/services_file.txt'

     0K ..                                                    100% 71.1M=0s

2024-04-26 20:56:34 (71.1 MB/s) - '/www/server/panel/plugin/mail_sys/services_file.txt' saved [2953/2953]

--2024-04-26 20:56:34--  https://na1-node.bt.cn/install/plugin/mail_sys_en/mail_server_init.py
Resolving na1-node.bt.cn (na1-node.bt.cn)... 128.1.164.196
Connecting to na1-node.bt.cn (na1-node.bt.cn)|128.1.164.196|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 29062 (28K) [application/octet-stream]
Saving to: '/www/server/panel/plugin/mail_sys/mail_server_init.py'

     0K .......... .......... ........                        100% 23.4M=0.001s

2024-04-26 20:56:34 (23.4 MB/s) - '/www/server/panel/plugin/mail_sys/mail_server_init.py' saved [29062/29062]

--2024-04-26 20:56:34--  https://na1-node.bt.cn/install/plugin/mail_sys_en/receive_mail.py
Resolving na1-node.bt.cn (na1-node.bt.cn)... 128.1.164.196
Connecting to na1-node.bt.cn (na1-node.bt.cn)|128.1.164.196|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 14545 (14K) [application/octet-stream]
Saving to: '/www/server/panel/plugin/mail_sys/receive_mail.py'

     0K .......... ....                                       100% 49.4M=0s

2024-04-26 20:56:35 (49.4 MB/s) - '/www/server/panel/plugin/mail_sys/receive_mail.py' saved [14545/14545]

--2024-04-26 20:56:35--  https://na1-node.bt.cn/install/plugin/mail_sys_en/index.html
Resolving na1-node.bt.cn (na1-node.bt.cn)... 128.1.164.196
Connecting to na1-node.bt.cn (na1-node.bt.cn)|128.1.164.196|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 213700 (209K) [text/html]
Saving to: '/www/server/panel/plugin/mail_sys/index.html'

     0K .......... .......... .......... .......... .......... 23%  161K 1s
    50K .......... .......... .......... .......... .......... 47%  161K 1s
   100K .......... .......... .......... .......... .......... 71%  322K 0s
   150K .......... .......... .......... .......... .......... 95%  322K 0s
   200K ........                                              100% 81.6M=0.9s

2024-04-26 20:56:37 (224 KB/s) - '/www/server/panel/plugin/mail_sys/index.html' saved [213700/213700]

--2024-04-26 20:56:37--  https://na1-node.bt.cn/install/plugin/mail_sys_en/info.json
Resolving na1-node.bt.cn (na1-node.bt.cn)... 128.1.164.196
Connecting to na1-node.bt.cn (na1-node.bt.cn)|128.1.164.196|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 308 [application/json]
Saving to: '/www/server/panel/plugin/mail_sys/info.json'

     0K                                                       100% 6.26M=0s

2024-04-26 20:56:38 (6.26 MB/s) - '/www/server/panel/plugin/mail_sys/info.json' saved [308/308]

--2024-04-26 20:56:38--  https://na1-node.bt.cn/install/plugin/mail_sys_en/icon.png
Resolving na1-node.bt.cn (na1-node.bt.cn)... 128.1.164.196
Connecting to na1-node.bt.cn (na1-node.bt.cn)|128.1.164.196|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 6509 (6.4K) [image/png]
Saving to: '/www/server/panel/plugin/mail_sys/icon.png'

     0K ......                                                100%  130M=0s

2024-04-26 20:56:38 (130 MB/s) - '/www/server/panel/plugin/mail_sys/icon.png' saved [6509/6509]

--2024-04-26 20:56:38--  https://na1-node.bt.cn/install/plugin/mail_sys_en/api.zip
Resolving na1-node.bt.cn (na1-node.bt.cn)... 128.1.164.196
Connecting to na1-node.bt.cn (na1-node.bt.cn)|128.1.164.196|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 228188 (223K) [application/zip]
Saving to: '/www/server/panel/plugin/mail_sys/static/api.zip'

     0K .......... .......... .......... .......... .......... 22%  161K 1s
    50K .......... .......... .......... .......... .......... 44%  162K 1s
   100K .......... .......... .......... .......... .......... 67%  323K 0s
   150K .......... .......... .......... .......... .......... 89%  323K 0s
   200K .......... .......... ..                              100% 32.2M=0.9s

2024-04-26 20:56:40 (240 KB/s) - '/www/server/panel/plugin/mail_sys/static/api.zip' saved [228188/228188]

--2024-04-26 20:56:40--  https://na1-node.bt.cn/install/plugin/mail_sys_en/ckeditor.zip
Resolving na1-node.bt.cn (na1-node.bt.cn)... 128.1.164.196
Connecting to na1-node.bt.cn (na1-node.bt.cn)|128.1.164.196|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 1718152 (1.6M) [application/zip]
Saving to: '/www/server/panel/BTPanel/static/ckeditor.zip'

     0K .......... .......... .......... .......... ..........  2%  149K 11s
    50K .......... .......... .......... .......... ..........  5%  149K 11s
   100K .......... .......... .......... .......... ..........  8%  269K 9s
   150K .......... .......... .......... .......... .......... 11%  299K 8s
   200K .......... .......... .......... .......... .......... 14%  296K 7s
   250K .......... .......... .......... .......... .......... 17%  299K 6s
   300K .......... .......... .......... .......... .......... 20% 32.6M 5s
   350K .......... .......... .......... .......... .......... 23%  296K 5s
   400K .......... .......... .......... .......... .......... 26%  302K 5s
   450K .......... .......... .......... .......... .......... 29% 28.8M 4s
   500K .......... .......... .......... .......... .......... 32%  300K 4s
   550K .......... .......... .......... .......... .......... 35% 37.2M 3s
   600K .......... .......... .......... .......... .......... 38%  300K 3s
   650K .......... .......... .......... .......... .......... 41% 50.8M 3s
   700K .......... .......... .......... .......... .......... 44%  300K 3s
   750K .......... .......... .......... .......... .......... 47% 37.3M 2s
   800K .......... .......... .......... .......... .......... 50%  302K 2s
   850K .......... .......... .......... .......... .......... 53% 24.4M 2s
   900K .......... .......... .......... .......... .......... 56% 45.8M 2s
   950K .......... .......... .......... .......... .......... 59%  304K 2s
  1000K .......... .......... .......... .......... .......... 62% 16.3M 2s
  1050K .......... .......... .......... .......... .......... 65% 25.5M 1s
  1100K .......... .......... .......... .......... .......... 68%  103M 1s
  1150K .......... .......... .......... .......... .......... 71%  304K 1s
  1200K .......... .......... .......... .......... .......... 74% 32.3M 1s
  1250K .......... .......... .......... .......... .......... 77% 46.7M 1s
  1300K .......... .......... .......... .......... .......... 80%  305K 1s
  1350K .......... .......... .......... .......... .......... 83% 33.3M 1s
  1400K .......... .......... .......... .......... .......... 86% 28.9M 0s
  1450K .......... .......... .......... .......... .......... 89% 46.1M 0s
  1500K .......... .......... .......... .......... .......... 92%  942K 0s
  1550K .......... .......... .......... .......... .......... 95%  445K 0s
  1600K .......... .......... .......... .......... .......... 98% 79.7M 0s
  1650K .......... .......... .......                         100% 31.9M=3.0s

2024-04-26 20:56:44 (551 KB/s) - '/www/server/panel/BTPanel/static/ckeditor.zip' saved [1718152/1718152]

|-Successify --- Command executed! ---

2024-04-26 20:56:35 (49.4 MB/s) - '/www/server/panel/plugin/mail_sys/receive_mail.py' saved [14545/14545]

--2024-04-26 20:56:35--  https://na1-node.bt.cn/install/plugin/mail_sys_en/index.html
Resolving na1-node.bt.cn (na1-node.bt.cn)... 128.1.164.196
Connecting to na1-node.bt.cn (na1-node.bt.cn)|128.1.164.196|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 213700 (209K) [text/html]
Saving to: '/www/server/panel/plugin/mail_sys/index.html'

     0K .......... .......... .......... .......... .......... 23%  161K 1s
    50K .......... .......... .......... .......... .......... 47%  161K 1s
   100K .......... .......... .......... .......... .......... 71%  322K 0s
   150K .......... .......... .......... .......... .......... 95%  322K 0s
   200K ........                                              100% 81.6M=0.9s

2024-04-26 20:56:37 (224 KB/s) - '/www/server/panel/plugin/mail_sys/index.html' saved [213700/213700]

--2024-04-26 20:56:37--  https://na1-node.bt.cn/install/plugin/mail_sys_en/info.json
Resolving na1-node.bt.cn (na1-node.bt.cn)... 128.1.164.196
Connecting to na1-node.bt.cn (na1-node.bt.cn)|128.1.164.196|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 308 [application/json]
Saving to: '/www/server/panel/plugin/mail_sys/info.json'

     0K                                                       100% 6.26M=0s

2024-04-26 20:56:38 (6.26 MB/s) - '/www/server/panel/plugin/mail_sys/info.json' saved [308/308]

--2024-04-26 20:56:38--  https://na1-node.bt.cn/install/plugin/mail_sys_en/icon.png
Resolving na1-node.bt.cn (na1-node.bt.cn)... 128.1.164.196
Connecting to na1-node.bt.cn (na1-node.bt.cn)|128.1.164.196|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 6509 (6.4K) [image/png]
Saving to: '/www/server/panel/plugin/mail_sys/icon.png'

     0K ......                                                100%  130M=0s

2024-04-26 20:56:38 (130 MB/s) - '/www/server/panel/plugin/mail_sys/icon.png' saved [6509/6509]

--2024-04-26 20:56:38--  https://na1-node.bt.cn/install/plugin/mail_sys_en/api.zip
Resolving na1-node.bt.cn (na1-node.bt.cn)... 128.1.164.196
Connecting to na1-node.bt.cn (na1-node.bt.cn)|128.1.164.196|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 228188 (223K) [application/zip]
Saving to: '/www/server/panel/plugin/mail_sys/static/api.zip'

     0K .......... .......... .......... .......... .......... 22%  161K 1s
    50K .......... .......... .......... .......... .......... 44%  162K 1s
   100K .......... .......... .......... .......... .......... 67%  323K 0s
   150K .......... .......... .......... .......... .......... 89%  323K 0s
   200K .......... .......... ..                              100% 32.2M=0.9s

2024-04-26 20:56:40 (240 KB/s) - '/www/server/panel/plugin/mail_sys/static/api.zip' saved [228188/228188]

--2024-04-26 20:56:40--  https://na1-node.bt.cn/install/plugin/mail_sys_en/ckeditor.zip
Resolving na1-node.bt.cn (na1-node.bt.cn)... 128.1.164.196
Connecting to na1-node.bt.cn (na1-node.bt.cn)|128.1.164.196|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 1718152 (1.6M) [application/zip]
Saving to: '/www/server/panel/BTPanel/static/ckeditor.zip'

     0K .......... .......... .......... .......... ..........  2%  149K 11s
    50K .......... .......... .......... .......... ..........  5%  149K 11s
   100K .......... .......... .......... .......... ..........  8%  269K 9s
   150K .......... .......... .......... .......... .......... 11%  299K 8s
   200K .......... .......... .......... .......... .......... 14%  296K 7s
   250K .......... .......... .......... .......... .......... 17%  299K 6s
   300K .......... .......... .......... .......... .......... 20% 32.6M 5s
   350K .......... .......... .......... .......... .......... 23%  296K 5s
   400K .......... .......... .......... .......... .......... 26%  302K 5s
   450K .......... .......... .......... .......... .......... 29% 28.8M 4s
   500K .......... .......... .......... .......... .......... 32%  300K 4s
   550K .......... .......... .......... .......... .......... 35% 37.2M 3s
   600K .......... .......... .......... .......... .......... 38%  300K 3s
   650K .......... .......... .......... .......... .......... 41% 50.8M 3s
   700K .......... .......... .......... .......... .......... 44%  300K 3s
   750K .......... .......... .......... .......... .......... 47% 37.3M 2s
   800K .......... .......... .......... .......... .......... 50%  302K 2s
   850K .......... .......... .......... .......... .......... 53% 24.4M 2s
   900K .......... .......... .......... .......... .......... 56% 45.8M 2s
   950K .......... .......... .......... .......... .......... 59%  304K 2s
  1000K .......... .......... .......... .......... .......... 62% 16.3M 2s
  1050K .......... .......... .......... .......... .......... 65% 25.5M 1s
  1100K .......... .......... .......... .......... .......... 68%  103M 1s
  1150K .......... .......... .......... .......... .......... 71%  304K 1s
  1200K .......... .......... .......... .......... .......... 74% 32.3M 1s
  1250K .......... .......... .......... .......... .......... 77% 46.7M 1s
  1300K .......... .......... .......... .......... .......... 80%  305K 1s
  1350K .......... .......... .......... .......... .......... 83% 33.3M 1s
  1400K .......... .......... .......... .......... .......... 86% 28.9M 0s
  1450K .......... .......... .......... .......... .......... 89% 46.1M 0s
  1500K .......... .......... .......... .......... .......... 92%  942K 0s
  1550K .......... .......... .......... .......... .......... 95%  445K 0s
  1600K .......... .......... .......... .......... .......... 98% 79.7M 0s
  1650K .......... .......... .......                         100% 31.9M=3.0s

2024-04-26 20:56:44 (551 KB/s) - '/www/server/panel/BTPanel/static/ckeditor.zip' saved [1718152/1718152]

|-Successify --- Command executed! ---
My Server Configuration (Contabo vps):
Debian 12
Ram- 16Gb
SSD- 400Gb
Please give solution.
thanks & regard