Synology RS3621xs Synology MailPlus Server Administrator s Guide - Based on Ma - Page 97

Enable greylist, Whitelist, Greylist, Blacklist, Security, Antispam - + default ip

Get Synology RS3621xs PDF manuals and user guides View all Synology RS3621xs manuals
Add to My Manuals
Save this manual to your list of manuals

Page 97 highlights

Chapter 9: Security Settings 6. Click OK to complete the settings. Enable greylist When there is a new inbound message, the system will check if there are records of the same IP address, sender, or recipient as that of this inbound message. If no records are found, the message will be considered suspicious, and an error message will be sent back to its sender, requesting the sender to send the message again later. According to SMTP standards, senders receiving error messages will try to send messages again at a later time. However, most spam senders will give up sending messages. When ordinary senders send messages again after a while, the system will receive them. The greylist mechanism uses this method to block spam. With the greylist enabled, the greylist will take the following default actions on emails from all sources: • Whitelist: Passes the test directly, and temporary error messages will not be sent back. • Greylist: Sends error messages to senders without communication history. • Blacklist: Rejects messages directly. Note: • The greylist mechanism may delay the delivery of legitimate messages. Please make sure you fully understand the greylist mechanism before enabling the greylist. Please refer to the following steps to enable greylist: 1. Go to Security > Antispam and tick the Enable greylist to enhance spam detection by temporarily rejecting suspicious incoming mails checkbox. 94

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 84
  • 85
  • 86
  • 87
  • 88
  • 89
  • 90
  • 91
  • 92
  • 93
  • 94
  • 95
  • 96
  • 97
  • 98
  • 99
  • 100
  • 101
  • 102
  • 103
  • 104
  • 105
  • 106
  • 107
  • 108
  • 109
  • 110
  • 111
  • 112
  • 113
  • 114
  • 115
  • 116
  • 117
  • 118
  • 119
  • 120
  • 121
  • 122
  • 123
  • 124
  • 125
  • 126
  • 127
  • 128
  • 129
  • 130
  • 131
  • 132
  • 133
  • 134
  • 135
  • 136
  • 137
  • 138
  • 139
  • 140
  • 141
  • 142
  • 143
  • 144
  • 145
  • 146
  • 147
  • 148
  • 149
  • 150
94
Chapter 9: Security Settings
6. Click
OK
to complete the settings.
Enable greylist
When there is a new inbound message, the system will check if there are records of the same
IP address, sender, or recipient as that of this inbound message. If no records are found, the
message will be considered suspicious, and an error message will be sent back to its sender,
requesting the sender to send the message again later. According to SMTP standards, senders
receiving error messages will try to send messages again at a later time. However, most spam
senders will give up sending messages. When ordinary senders send messages again after a
while, the system will receive them. The greylist mechanism uses this method to block spam.
With the greylist enabled, the greylist will take the following default actions on emails from all
sources:
•
Whitelist
: Passes the test directly, and temporary error messages will not be sent back.
•
Greylist
: Sends error messages to senders without communication history.
•
Blacklist
: Rejects messages directly.
Note:
• The greylist mechanism may delay the delivery of legitimate messages. Please make sure
you fully understand the greylist mechanism before enabling the greylist.
Please refer to the following steps to enable greylist:
1. Go to
Security
>
Antispam
and tick the
Enable greylist to enhance spam detection by
temporarily rejecting suspicious incoming mails
checkbox.