diff --git a/doc.go b/doc.go
index c14170e..9498ee0 100644
--- a/doc.go
+++ b/doc.go
@@ -1008,7 +1008,7 @@ Print settings and members of alias.
 
 # mox config alias add
 
-Add new alias with one or more addresses.
+Add new alias with one or more addresses and public posting enabled.
 
 	usage: mox config alias add alias@domain rcpt1@domain ...
 
diff --git a/main.go b/main.go
index 0ac8c14..8fbca8a 100644
--- a/main.go
+++ b/main.go
@@ -770,13 +770,13 @@ func ctlcmdConfigAliasPrint(ctl *ctl, address string) {
 
 func cmdConfigAliasAdd(c *cmd) {
 	c.params = "alias@domain rcpt1@domain ..."
-	c.help = `Add new alias with one or more addresses.`
+	c.help = `Add new alias with one or more addresses and public posting enabled.`
 	args := c.Parse()
 	if len(args) < 2 {
 		c.Usage()
 	}
 
-	alias := config.Alias{Addresses: args[1:]}
+	alias := config.Alias{PostPublic: true, Addresses: args[1:]}
 
 	mustLoadConfig()
 	ctlcmdConfigAliasAdd(xctl(), args[0], alias)
diff --git a/webadmin/admin.js b/webadmin/admin.js
index 3e0f15d..735d0fb 100644
--- a/webadmin/admin.js
+++ b/webadmin/admin.js
@@ -2358,7 +2358,7 @@ const domain = async (d) => {
 		e.stopPropagation();
 		const alias = {
 			Addresses: aliasAddresses.value.split('\n').map(s => s.trim()).filter(s => !!s),
-			PostPublic: false,
+			PostPublic: true,
 			ListMembers: false,
 			AllowMsgFrom: false,
 			// Ignored:
@@ -2554,7 +2554,7 @@ const domainAlias = async (d, aliasLocalpart) => {
 		e.preventDefault();
 		e.stopPropagation();
 		check(aliasFieldset, client.AliasUpdate(aliasLocalpart, d, postPublic.checked, listMembers.checked, allowMsgFrom.checked));
-	}, aliasFieldset = dom.fieldset(style({ display: 'flex', flexDirection: 'column', gap: '.5ex' }), dom.label(postPublic = dom.input(attr.type('checkbox'), alias.PostPublic ? attr.checked('') : []), ' Public, anyone can post instead of only members'), dom.label(listMembers = dom.input(attr.type('checkbox'), alias.ListMembers ? attr.checked('') : []), ' Members can list other members'), dom.label(allowMsgFrom = dom.input(attr.type('checkbox'), alias.AllowMsgFrom ? attr.checked('') : []), ' Allow messages to use the alias address in the message From header'), dom.div(style({ marginTop: '1ex' }), dom.submitbutton('Save')))), dom.br(), dom.h2('Members'), dom.p('Members receive messages sent to the alias. If a member address is in the message From header, the member will not receive the message.'), dom.table(dom.thead(dom.tr(dom.th('Address'), dom.th('Account'), dom.th())), dom.tbody((alias.Addresses || []).map((address, index) => {
+	}, aliasFieldset = dom.fieldset(style({ display: 'flex', flexDirection: 'column', gap: '.5ex' }), dom.label(postPublic = dom.input(attr.type('checkbox'), alias.PostPublic ? attr.checked('') : []), ' Public, anyone is allowed to send to the alias, instead of only members of the alias', attr.title('Based on address in message From header, which is assumed to be DMARC-like verified. If this setting is disabled and a non-member sends a message to the alias, the message is rejected.')), dom.label(listMembers = dom.input(attr.type('checkbox'), alias.ListMembers ? attr.checked('') : []), ' Members can list other members'), dom.label(allowMsgFrom = dom.input(attr.type('checkbox'), alias.AllowMsgFrom ? attr.checked('') : []), ' Allow messages to use the alias address in the message From header'), dom.div(style({ marginTop: '1ex' }), dom.submitbutton('Save')))), dom.br(), dom.h2('Members'), dom.p('Members receive messages sent to the alias. If a member address is in the message From header, the member will not receive the message.'), dom.table(dom.thead(dom.tr(dom.th('Address'), dom.th('Account'), dom.th())), dom.tbody((alias.Addresses || []).map((address, index) => {
 		const pa = (alias.ParsedAddresses || [])[index];
 		return dom.tr(dom.td(prewrap(address)), dom.td(dom.a(pa.AccountName, attr.href('#accounts/' + pa.AccountName))), dom.td(dom.clickbutton('Remove', async function click(e) {
 			await check(e.target, client.AliasAddressesRemove(aliasLocalpart, d, [address]));
diff --git a/webadmin/admin.ts b/webadmin/admin.ts
index ab22e4e..4087efd 100644
--- a/webadmin/admin.ts
+++ b/webadmin/admin.ts
@@ -1347,7 +1347,7 @@ const domain = async (d: string) => {
 				e.stopPropagation()
 				const alias: api.Alias = {
 					Addresses: aliasAddresses.value.split('\n').map(s => s.trim()).filter(s => !!s),
-					PostPublic: false,
+					PostPublic: true,
 					ListMembers: false,
 					AllowMsgFrom: false,
 					// Ignored:
@@ -1814,7 +1814,8 @@ const domainAlias = async (d: string, aliasLocalpart: string) => {
 				style({display: 'flex', flexDirection: 'column', gap: '.5ex'}),
 				dom.label(
 					postPublic=dom.input(attr.type('checkbox'), alias.PostPublic ? attr.checked('') : []),
-					' Public, anyone can post instead of only members',
+					' Public, anyone is allowed to send to the alias, instead of only members of the alias',
+					attr.title('Based on address in message From header, which is assumed to be DMARC-like verified. If this setting is disabled and a non-member sends a message to the alias, the message is rejected.'),
 				),
 				dom.label(
 					listMembers=dom.input(attr.type('checkbox'), alias.ListMembers ? attr.checked('') : []),