errors when creating users

[nickbreen]

Error:
Array
(
    [curl] => 
    [Error] => Array
        (
            [Type] => Sender
            [Code] => InvalidParameterValue
            [Message] => Illegal address
        )

    [RequestId] => bbbba154-f094-11e5-8e09-a9b5be76ef0d
)
Error:
Array
(
    [curl] => 
    [Error] => Array
        (
            [Type] => Sender
            [Code] => InvalidParameterValue
            [Message] => Illegal address
        )

    [RequestId] => bc22c80a-f094-11e5-89de-173d7616c49e
)
Success: Created user 2.
Password: !JeWPf2QQc!s
Error:
Array
(
    [curl] => 
    [Error] => Array
        (
            [Type] => Sender
            [Code] => InvalidParameterValue
            [Message] => Illegal address
        )

    [RequestId] => bcfa3bc0-f094-11e5-8c0d-6738bc86c51c
)
Error:
Array
(
    [curl] => 
    [Error] => Array
        (
            [Type] => Sender
            [Code] => InvalidParameterValue
            [Message] => Illegal address
        )

    [RequestId] => bd5f6662-f094-11e5-9ff4-353490ec673a
)
Success: Created user 3.
Password: s4wAs#4kcaNM

[nickbreen]

On fresh setup, prior to checking WP-SES configuration.

wp@wp-1:~$ wp user create test nick+test@foobar.net.nz
Error:
Array
(
    [curl] => 
    [Error] => Array
        (
            [Type] => Sender
            [Code] => InvalidParameterValue
            [Message] => Illegal address
        )

    [RequestId] => f3d21ded-f0a2-11e5-bbe7-01506a358138
)
Error:
Array
(
    [curl] => 
    [Error] => Array
        (
            [Type] => Sender
            [Code] => InvalidParameterValue
            [Message] => Illegal address
        )

    [RequestId] => f4379681-f0a2-11e5-bbe7-01506a358138
)
Success: Created user 2.
Password: %^4hh8(G2STX

[nickbreen]

Checked WP_SES settings: OK.

[nickbreen]

Sending a test email from WP-SES setting page works perfectly.