Contacts can be imported using a
    comma-separated-value(CSV) file. In the Import
    navigation menu, you will find a template that
    you can use to import new contacts. 
The
    following fields are required to appear in the import file headers. If any of these fields does not appear in the header, then the import will fail and no data will be imported.
- FirstName - 64 characters max
- LastName - 64 characters max
- Email - 256 characters max
- Phone - 32 characters max
- TitleOrPosition- 64 characters max
- Company - 256 characters max
The following fields are completely optional and can be included or excluded from the import file headers:
- Tags - 128 characters max for each tag. See
        below for formatting.
- CustomFields* - Name: 50 characters max.
        Value: 1024 characters max.
* : See below for details, as the
    heading will be different for each Custom
    Field.
When importing, you may add Contacts to a Sequence as part of the import process. The following fields are available to use for this operation:
- SequenceId - Integer representing the Id of the Sequence this Contact should be added to.
- Step - 0 or 1. Setting this to 0 represents the Sequence Buffer while 1 represents Step 1. (Default: 0)
- ProcessAfter - Date in ISO-8601 format. ie: YYYY-MM-DDTHH:MM+00:00. (Default: Current UTC date)
- FromAddress - Email address to associate with the Contact in the Sequence.
NOTE: When doing this, the SequenceId and FromAddress are both required.
Common Import Problems
The most common problems encountered
        during an import are as follows:
- The maximum length of a field has been
        exceeded
- A header row was not included or all of
        the required column header names were not
        found in the import file. Many times, this
        is the result of a space or underscore
        being added into the column header such as
        "First Name" instead of "FirstName".
Tags
If you wish to add more than one tag to a
    Contact during the import, then the Tags field
    should use a comma separated list of tag
    names enclosed in double quotes to indicate
    the tag names are all part of the "Tags"
    column.
Example:
FirstName,LastName,Email,Phone,TitleOrPosition,Company,TagsJoe,User,joe@test.com,,,,"tag1,tag2"
Removing Tags
If you wish to delete a tag from
        a Contact, then you should prefix the name
        of the tag with a 'dash' character.
Example:
In the following example, 
tag1 will be added if it doesn't
    exist and tag2 will be removed if
    it already exists.FirstName,LastName,Email,Phone,TitleOrPosition,Company,TagsJoe,User,joe@test.com,,,,"tag1,-tag2"
Custom Fields
You can optionally apply Custom Fields to a
    Contact during the import process by appending
    an additional column for each Custom Field
    with a prefix of "cf_".
Example:
FirstName,LastName,Email,Phone,TitleOrPosition,Company,Tags,cf_MyField1,cf_MyField2Joe,User,joe@test.com,,,,"tag1,tag2",,This is my second custom field
Using Custom Fields in an
        Email Sequence
Custom Fields for a Contact may
        also be used
        inside of an email template by referring
        to
        the Custom Field name from the Liquid
        template
        engine.
Example:
Hi {{ contact.first_name}},We met last week at {{contact.cf.conference_name}} and I wanted to reconnect with you.
Adding Contacts to a Sequence
When you are adding Contacts to a Sequence, you must specify both the SequenceId and the FromAddress. Additionally, the FromAddress must match an SmtpServerId which is Active and has an associated Mailbox which is also Active.
If any of these conditions are not met, then the Contact will not be added to the Sequence.
Remember that a Contact cannot be added to a Sequence more than once, so attempts to add a Contact to a Sequence it is already part of will be ignored.